Liquid composition, shaped article, and shaped article production method

ABSTRACT

A liquid composition contains a cellulosic material constituted by a material containing at least one of cellulose and a cellulose derivative, and an ionic liquid having a functional group with reactivity. It is preferred that the ionic liquid has an imidazolium salt structure. It is also preferred that the functional group with reactivity contains a carbon-carbon double bond.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Japanese Patent Application No. 2014-236297 filed on Nov. 21, 2014. The entire disclosures of Japanese Patent Application No. 2014-236297 is hereby incorporated herein by reference.

BACKGROUND

1. Technical Field

The present invention relates to a liquid composition, a shaped article, and a shaped article production method.

2. Related Art

Cellulose is a recyclable resource and is accumulated abundantly on earth, and also has excellent biocompatibility and degradability, and therefore is an environmentally friendly material. Accordingly, cellulose has attracted attention recently, and its effective utilization has been demanded (see, for example, JP-A-7-268724).

However, in the past, cellulose was mostly used in paper products such as printing paper and corrugated cardboard, and other than these, it was merely used in fibers (cellulose fibers) and the like. Therefore, there was a problem that various advantageous characteristics of cellulose are not fully utilized.

In particular, cellulose has low solubility in various solvents and it is difficult to prepare a high concentration solution. Therefore, when cellulose was formed into a given shape, it was difficult to prepare a liquid composition having high uniformity, so that it was difficult to produce a shaped article having high dimensional accuracy. In particular, recently, a three-dimensional shaping method for obtaining a three-dimensionally shaped article using an inkjet method or the like has attracted attention, however, it was extremely difficult to stably eject a composition containing cellulose by an inkjet method or the like.

Further, cellulose has been known to be able to constituting a member having excellent mechanical strength because of its chemical structure, however, it has not yet been applied on a practical level to a member having high strength and high durability which sufficiently exhibits the characteristics of cellulose.

SUMMARY

An advantage of some aspects of the invention is to provide a liquid composition which contains a cellulosic material and can be favorably used for producing a shaped article having excellent dimensional accuracy and strength, to provide a shaped article which contains a cellulosic material and has excellent dimensional accuracy and strength, and to provide a shaped article production method capable of efficiently producing a shaped article which contains a cellulosic material and has excellent dimensional accuracy and strength.

Such an advantage is achieved by the invention described below.

A liquid composition according to an aspect of the invention contains a cellulosic material constituted by a material containing at least one of cellulose and a cellulose derivative, and an ionic liquid having a functional group with reactivity.

According to this configuration, a liquid composition which can be favorably used for producing a shaped article which contains a cellulosic material and has excellent dimensional accuracy and strength can be provided.

In the liquid composition according to the aspect of the invention, it is preferred that the ionic liquid has an imidazolium salt structure.

According to this configuration, the solubility of the cellulosic material in the ionic liquid (reactive ionic liquid) can be made excellent, so that a liquid composition containing the cellulosic material at a higher concentration can be favorably prepared, and thus, a shaped article containing the cellulosic material can be produced with higher dimensional accuracy. Further, when the liquid composition contains a reactive ionic liquid having an imidazolium salt structure, the ejection stability of the liquid composition containing the cellulosic material by an inkjet method or the like can be made more excellent, and therefore, the productivity of the shaped article can be made more excellent.

In the liquid composition according to the aspect of the invention, it is preferred that the functional group with reactivity contains a carbon-carbon double bond.

According to this configuration, the reactivity of the ionic liquid (reactive ionic liquid) can be made excellent, and therefore, the productivity of a shaped article to be produced using the liquid composition can be made more excellent. Further, the unreacted reactive ionic liquid (in a liquid state) can be effectively prevented from being undesirably contained in the shaped article to be produced. Further, the chemical stability of a covalent bond to be formed by the reaction can be made more excellent. As a result, the durability, strength, and reliability of the shaped article can be made more excellent. In addition, the range of choice of a compound which reacts with the reactive ionic liquid (a compound which can react with the reactive functional group of the reactive ionic liquid) is expanded, and thus, the range of design of the reactive ionic liquid is expanded.

In the liquid composition according to the aspect of the invention, it is preferred that the functional group with reactivity is a (meth)acryloyl group.

According to this configuration, the reactivity of the ionic liquid (reactive ionic liquid) can be made more excellent, and therefore, the productivity of a shaped article can be made more excellent. Further, the unreacted reactive ionic liquid can be more effectively prevented from being undesirably contained in the final shaped article. Further, the chemical stability of a covalent bond to be formed by the reaction can be made more excellent. As a result, the durability, strength, and reliability of the shaped article can be made more excellent. In addition, the range of choice of a compound which reacts with the reactive ionic liquid (a compound which can react with the reactive functional group of the reactive ionic liquid) is expanded, and thus, the range of design of the reactive ionic liquid is further expanded.

In the liquid composition according to the aspect of the invention, it is preferred that when the content of the ionic liquid in the liquid composition is represented by Xs (mass %) and the content of the cellulosic material in the liquid composition is represented by Xc (mass %), the liquid composition satisfies the following relationship: 1≦Xc/Xs≦40.

According to this configuration, while more effectively exhibiting the advantageous characteristics intrinsic to the cellulosic material, the dimensional accuracy, mechanical strength, durability, reliability, and the like of a shaped article to be produced using the liquid composition can be made more excellent.

In the liquid composition according to the aspect of the invention, it is preferred that the liquid composition contains the cellulose derivative having a liquid crystalline moiety.

According to this configuration, the mechanical strength, durability, reliability, and the like of a shaped article to be produced using the liquid composition can be made more excellent.

A shaped article according to another aspect of the invention is produced using the liquid composition according to the aspect of the invention.

According to this configuration, a shaped article which contains the cellulosic material and has excellent dimensional accuracy and strength can be provided.

A shaped article production method according to still another aspect of the invention is a method for producing a three-dimensionally shaped article by performing a layer forming step of forming a layer using a composition a plurality of times and stacking the layers, wherein the liquid composition according to the aspect of the invention is applied to a region where the three-dimensionally shaped article is to be formed, and thereafter, a chemical reaction involving the functional group with reactivity is allowed to proceed.

According to this configuration, a shaped article production method capable of efficiently producing a shaped article which contains the cellulosic material and has excellent dimensional accuracy and strength can be provided.

In the shaped article production method according to the aspect of the invention, it is preferred that the liquid composition is applied by an inkjet method.

According to this configuration, even if a pattern in which the liquid composition is applied has a finer shape, the liquid composition can be applied with higher reproducibility. As a result, the dimensional accuracy of a finally obtained shaped article can be made higher. Further, in the related art, in the case where a shaped article constituted by a material containing a cellulosic material is tried to be produced using an inkjet method, a problem that the dimensional accuracy or the like of the shaped article is low occurred more remarkably. However, according to the invention, even in the case where an inkjet method is used, the occurrence of such a problem can be reliably prevented. That is, in the case where the liquid composition is applied using an inkjet method, the effect of the invention is more remarkably exhibited.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.

FIGS. 1A to 1H show cross-sectional views schematically illustrating respective steps in a first embodiment of a shaped article production method according to the invention.

FIGS. 2A to 2F show cross-sectional views schematically illustrating respective steps in a second embodiment of a shaped article production method according to the invention.

FIG. 3 is a cross-sectional view schematically showing a first embodiment of a production apparatus to be used for producing a shaped article according to the invention.

FIG. 4 is a cross-sectional view schematically showing a second embodiment of a production apparatus to be used for producing a shaped article according to the invention.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings.

Liquid Composition

First, a liquid composition according to the invention will be described in detail.

The liquid composition according to the invention contains a cellulosic material constituted by a material containing at least one of cellulose and a cellulose derivative, and an ionic liquid.

The ionic liquid is a salt present in a liquid state and generally has an ionic size (the size of an atomic group functioning as an ion) larger than that of a normal salt in the form of a solid.

The ionic liquid contained in the liquid composition according to the invention has a functional group with reactivity (reactive functional group).

Such an ionic liquid (reactive ionic liquid) can favorably dissolve a cellulosic material, and thus can dissolve the cellulosic material at a high concentration. Due to this, the cellulosic material is dissolved in the ionic liquid (reactive ionic liquid) having a reactive functional group at a high concentration and uniformly, so that the formability when a shaped article having a given shape is produced can be made excellent, and thus, the dimensional accuracy of the shaped article to be produced can be made excellent. In particular, a method in which the liquid composition is ejected such as an inkjet method requires that the liquid composition should have a relatively low viscosity and the composition in the liquid composition should be uniform, however, the liquid composition containing a cellulosic material and the ionic liquid (reactive ionic liquid) as described above can satisfy such a requirement. Further, in a method in which the liquid composition is ejected such as an inkjet method, when the liquid composition in which the dilution ratio of a solid component is high is used, a formed pattern is largely deformed as the solvent is removed, and therefore, there is a problem that the dimensional accuracy of the finally obtained shaped article is significantly deteriorated. However, according to the invention, it is not necessary to remove the ionic liquid from the liquid composition after ejection, and therefore, the occurrence of such a problem can be effectively prevented. Further, the ejection of the liquid composition by an inkjet method or the like can be performed smoothly, and thus, the productivity of the shaped article can be made excellent. Therefore, the liquid composition can be favorably applied also to a three-dimensional shaping method using an inkjet method or the like.

Further, by including the ionic liquid (reactive ionic liquid) having a functional group with reactivity (reactive functional group) in the liquid composition, a reaction product of the reactive ionic liquid can be included in the shaped article to be produced using the liquid composition. As a result, the shaped article to be produced is, for example, configured such that the cellulosic material is favorably fixed by the reaction product of the reactive ionic liquid, and thus has excellent mechanical strength, durability, and the like.

Further, since the cellulosic material can be included in the liquid composition at a high concentration, in the shaped particle to be produced using the liquid composition, the advantageous characteristics intrinsic to the cellulosic material can be sufficiently exhibited.

Cellulosic Material

As described above, the liquid composition according to the invention contains at least one of cellulose and a cellulose derivative.

Cellulose is a compound in which β-glucose is polymerized through a glycoside bond, however, the cellulose derivative as used herein may be any as long as it is a compound capable of being derived from cellulose by a chemical reaction, and examples thereof include a cellulose derivative obtained by substituting at least part of the hydroxy groups of cellulose with another substituent (including a cellulose derivative obtained by a condensation reaction of at least part of the hydroxy groups of cellulose with another compound, etc.).

The substituent may be introduced into all the repeating units (glucose structures) in the same manner, or may be introduced into only part of the repeating units (glucose structures). Further, the substituent may be introduced into a position which is different among the repeating units (glucose structures).

Cellulose has excellent characteristics, for example, has a light weight and a high strength, and also has excellent biocompatibility and degradability and therefore is environmentally friendly, etc. A shaped article to be produced using the liquid composition according to the invention containing a cellulosic material can effectively exhibit the excellent characteristics as described above.

In the case where the liquid composition according to the invention contains a cellulose derivative, the cellulose derivative may be any, but is preferably a cellulose derivative having an ionic moiety as a chemical structure common to the ionic liquid.

According to this, the cellulose derivative has a higher solubility in the ionic liquid (reactive ionic liquid) having a functional group with reactivity contained in the liquid composition according to the invention. Due to this, the cellulose derivative in the liquid composition can be dissolved at a higher concentration and more uniformly. As a result, the formability when a shaped article having a given shape is produced can be made more excellent, and thus, the dimensional accuracy of the shaped article to be produced can be made more excellent.

Further, the cellulose derivative containing an ionic moiety has a large intermolecular binding force, and therefore, the mechanical strength, durability, and the like of the shaped article to be produced using the liquid composition can be made more excellent.

Examples of a cation constituting the ionic liquid (ionic moiety) include various cations such as imidazole-based, pyridine-based, alicyclic amine-based, and aliphatic amine-based cations.

Examples of an anion constituting the ionic liquid (ionic moiety) include various anions such as halogen-based anions (such as bromide anions and triflate anions), boron-based anions (such as tetraphenyl borate anions), and phosphorus-based anions (such as hexafluorophosphate anions).

Specific examples of the ionic liquid include N-methyl-N-propylpyrrolidinium bis(fluorosulfonyl)imide, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide, dimethylpropylimidazolium iodide, butylmethylimidazolium iodide, 1,2-dimethyl-3-n-propylimidazolium iodide, 1-methyl-3-n-hexylimidazolium iodide, 1,2-dimethyl-3-ethylimidazolium trifluoromethanesulfonate, 1-methyl-3-butylimidazolium nonafluorobutylsulfonate, 1-methyl-3-ethylimidazolium bis(trifluoromethyl)sulfonylimide, 1-methyl-3-n-hexylimidazolium bis(trifluoromethyl)sulfonylimide, 1-methyl-3-n-hexylimidazolium dicyanamide, lithium bisfluorosulfonylimide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), 1-methyl-3-propylimidazolium bis(trifluorosulfonyl)imide, 1-ethyl-3-butylimidazolium tetrafluoroborate, and 1-hexyl-3-methylimidazolium hexafluorophosphate.

In particular, the ionic moiety of the cellulose derivative preferably has an imidazolium salt structure.

According to this, the solubility of the cellulose derivative in the reactive ionic liquid constituting the liquid composition can be made more excellent, so that the liquid composition containing the cellulose derivative at a higher concentration can be favorably prepared, and thus, a shaped article can be produced with higher dimensional accuracy. Further, the mechanical strength, durability, and the like of the shaped article to be produced using the liquid composition can be made more excellent. Further, when the ionic moiety of the cellulose derivative has an imidazolium salt structure, the ejection stability of the liquid composition by an inkjet method or the like can be made more excellent, and therefore, the productivity of the shaped article can be made more excellent.

Examples of the ionic moiety include moieties represented by the following formula (3).

In the formula (3), R⁷ is a hydrogen atom (H) or an alkyl group.

The ionic moiety may be introduced into any position of the cellulose derivative, but is preferably introduced into a hydroxy group bonded to the carbon atom at position 6 of β-glucose constituting cellulose by a chemical reaction. That is, it is preferred that the ionic moiety is introduced into R³ in the following formula (2).

In the formula (2), R¹, R², R³, R⁴, and R⁵ each independently represent a hydrogen atom or a substituent, provided that at least one functional group containing the ionic moiety is introduced into the molecule.

According to this, the ionic moiety can be efficiently exposed to the outside of the molecule of the cellulose derivative. As a result, the solubility of the cellulose derivative in the reactive ionic liquid can be made more excellent, so that the formability and productivity of the shaped article using the liquid composition, and the dimensional accuracy and the like of the shaped article can be made more excellent, and thus, this configuration can be more favorably applied to a three-dimensional shaping method using an inkjet method or the like. Further, the mechanical strength and durability of the shaped article to be produced using the liquid composition can be made more excellent. Further, the synthesis of the cellulose derivative serving as the constituent component of the liquid composition can be efficiently performed. As a result, this configuration can also contribute to the reduction of the production cost of the shaped article (cellulosic member).

It is preferred that a plurality of ionic moieties are introduced into the molecule of the cellulose derivative.

According to this, the effect of having the ionic moiety as described above is more remarkably exhibited, so that the solubility of the cellulose derivative in the reactive ionic liquid can be made more excellent, and also the formability and productivity of the shaped article using the liquid composition, and the dimensional accuracy and the like of the shaped article can be made more excellent, and thus, this configuration can be more favorably applied to a three-dimensional shaping method using an inkjet method or the like. Further, the mechanical strength and durability of the shaped article to be produced using the liquid composition can be made more excellent.

In particular, it is preferred that a plurality of ionic moieties are introduced into a repeating unit of a polymer chain (side chain) having a repeating structure introduced into a cellulose backbone structure (basic structure).

According to this, the solubility of the cellulose derivative in a reactive ionic liquid can be made more excellent, so that the formability and productivity of the shaped article using the liquid composition, and the dimensional accuracy and the like of the shaped article can be made more excellent, and thus, this configuration can be more favorably applied to a three-dimensional shaping method using an inkjet method or the like. Further, the mechanical strength and durability of the shaped article to be produced using the liquid composition can be made more excellent. Further, the synthesis of the cellulose derivative serving as the constituent component of the liquid composition can be efficiently performed. As a result, this configuration can also contribute to the reduction of the production cost of the shaped article (cellulosic member).

Specific examples of a preferred cellulose derivative satisfying such conditions include cellulose derivatives represented by the following formula (7).

In the formula (7), n and m are each independently an integer of 2 or more, l is an integer of 1 or more, R¹, R², R⁴, and R⁵ are each independently a hydrogen atom (H) or an acetyl group (CH₃CO), and R⁷ is a hydrogen atom (H) or an alkyl group.

The cellulose derivative may have a liquid crystalline moiety.

According to this, in the shaped article (cellulosic member) to be produced using the liquid composition, the effect of alignment (arrangement) of a liquid crystalline component (liquid crystalline moiety) can be reflected in the entire cellulose derivative, and thus, the mechanical strength, durability, reliability, and the like of the shaped article can be made more excellent. In particular, as described above, the liquid composition according to the invention contains the reactive ionic liquid which has high solubility of a cellulosic material, and therefore, in the shaped article to be produced using the liquid composition in a state where the cellulose derivative is favorably dissolved in the reactive ionic liquid, the cellulose derivative (liquid crystalline moiety) can be favorably aligned, and thus, the mechanical strength, durability, reliability, and the like of the shaped article can be made more excellent.

Examples of the liquid crystalline moiety (atomic group with liquid crystallinity) include moieties represented by the following formulae (6).

The liquid crystalline moiety (liquid crystalline functional group) may be introduced into any position of the cellulose derivative, but is preferably introduced into a hydroxy group bonded to the carbon atom at position 6 of β-glucose constituting cellulose by a chemical reaction. That is, it is preferred that the functional group is introduced into R³ in the above formula (2).

According to this, the effect of the liquid crystalline moiety (liquid crystalline functional group) on the alignment of the cellulose derivative can be more remarkably exhibited, and thus, the durability, strength, and reliability of the shaped article can be made more excellent. Further, the synthesis of the cellulose derivative serving as the constituent component of the liquid composition can be efficiently performed. As a result, this configuration can also contribute to the reduction of the production cost of the shaped article.

It is preferred that a plurality of liquid crystalline moieties (liquid crystalline functional groups) are introduced into the molecule of the cellulose derivative.

According to this, the cellulose derivative in the shaped article can be more favorable arranged, and thus, the mechanical strength, durability, and reliability of the shaped article can be made more excellent.

In particular, it is preferred that a plurality of liquid crystalline moieties (liquid crystalline functional groups) are introduced into a repeating unit of a polymer chain (side chain) having a repeating structure introduced into a cellulose backbone structure (basic structure).

According to this, for example, in the cellulose derivative molecule, the liquid crystalline moieties (liquid crystalline functional groups) can be more reliably made to exist regularly. Further, the conditions for a plurality of liquid crystalline moieties (liquid crystalline functional groups) of the cellulose derivative molecule can be favorably aligned. As a result, the cellulose derivative can be made to exist at a high density in the shaped article, and thus, the mechanical strength, durability, and reliability of the shaped article can be made more excellent.

It is preferred that the cellulose derivative has the ionic moieties and the liquid crystalline moieties in the form of blocks, respectively. In other words, it is preferred that the cellulose derivative has a block containing a plurality of ionic moieties and a block containing a plurality of liquid crystalline moieties.

According to this, both of the effect of having the ionic moiety and the effect of having a plurality of liquid crystalline moieties can be more remarkably exhibited, and thus, the dimensional accuracy, mechanical strength, and the like of the shaped article to be produced can be made more excellent.

Specific examples of a preferred cellulose derivative satisfying such conditions include cellulose derivatives represented by the following formula (8).

In the formula (8), l, m, and n are each independently an integer of 2 or more, R¹, R², R⁴, and R⁵ are each independently a hydrogen atom (H) or an acetyl group (CH₃CO), R⁸ is a group represented by the following formula (9), and R⁹ is a group represented by the following formula (10) or (11).

In the formula (9), k is an integer of 1 or more, and R⁷ is a hydrogen atom (H) or an alkyl group.

In the formulae (10) and (11), j is an integer of 1 or more, and R⁶ is a hydrogen atom (H) or an alkyl group.

Further, the cellulose derivative may have a functional group (reactive functional group) which binds the molecular chains of the cellulose derivative or the cellulose derivative and the reactive ionic liquid through a covalent bond.

In this manner, by binding the molecular chains of the cellulose derivative or the cellulose derivative and the reactive ionic liquid through a covalent bond, the mechanical strength, reliability, and the like of the shaped article can be made more excellent, and also the advantageous characteristics (for example, high strength, light weight, biosafety, environmental safety, etc.) intrinsic to the cellulosic material can be more effectively exhibited.

Such a functional group (reactive functional group) may be a group which directly binds the molecules of the cellulose derivative or the cellulose derivative and the reactive ionic liquid or may be a group which binds the molecules or the cellulose derivative and the reactive ionic liquid through another atom (at least one atom).

Examples of the functional group (reactive functional group) include a group containing a carbon-carbon double bond, a hydroxy group, and a carboxyl group, however, a group containing a carbon-carbon double bond is preferred.

According to this, the reactivity of the cellulose derivative can be made excellent, and the productivity of the shaped article to be produced using the liquid composition can be made more excellent. In addition, the unreacted cellulose derivative can be effectively prevented from being undesirably contained much in the shaped article to be produced. Further, the chemical stability of the covalent bond to be formed by the reaction can be made more excellent. As a result, the durability, strength, and reliability of the shaped article can be made more excellent. Further, the range of choice of a compound which reacts with the cellulose derivative (a compound which can react with the reactive functional group of the cellulose derivative) is expanded, and thus, the range of design of the shaped article is expanded.

Examples of the functional group (reactive functional group) containing a carbon-carbon double bond include a vinyl group and a (meth)acryloyl group, however, a (meth)acryloyl group is preferred.

According to this, the reactivity of the cellulose derivative can be made more excellent, and thus, the productivity of the shaped article can be made more excellent. In addition, the unreacted cellulose derivative can be more effectively prevented from being undesirably contained much in the final shaped article. Further, the chemical stability of the covalent bond to be formed by the reaction can be made more excellent. As a result, the durability, strength, and reliability of the shaped article can be made more excellent. Further, the range of choice of a compound which reacts with the cellulose derivative (a compound which can react with the reactive functional group of the cellulose derivative) is expanded, and thus, the range of design of the shaped article is expanded.

The reactive functional group may be introduced into any position of the cellulose derivative, but is preferably introduced into a side chain of the cellulose derivative different from the cellulose backbone structure (basic backbone structure).

According to this, the effect of having the reactive functional group can be effectively exhibited while more effectively exhibiting the advantageous characteristics (for example, high strength, light weight, biosafety, environmental safety, etc.) intrinsic to cellulose. Further, the side chain of the cellulose derivative generally has higher reactivity than the cellulose backbone structure (basic backbone structure), and therefore, the reaction involving the reactive functional group can be allowed to more efficiently proceed.

In particular, the reactive functional group is preferably introduced into a hydroxy group bonded to the carbon atom at position 6 of β-glucose constituting cellulose by a chemical reaction. That is, it is preferred that the reactive functional group is introduced into R³ in the above formula (2).

According to this, the steric hindrance of the reactive functional group can be made small, or the like, and thus, the reactivity of the cellulose derivative can be made excellent, and thus, the productivity of the shaped article can be made more excellent. In addition, the unreacted cellulose derivative can be prevented from being undesirably contained much in the final shaped article. Accordingly, the durability, strength, and reliability of the shaped article can be made more excellent. Further, the synthesis of the cellulose derivative serving as the constituent component of the liquid composition can be efficiently performed. As a result, this configuration can also contribute to the reduction of the production cost of the shaped article.

Further, the reactive functional group is preferably introduced into the cellulose backbone through at least one carbon-carbon single bond in the basic cellulose structure.

According to this, the reactivity of the reactive functional group can be made more excellent, and thus, the productivity and the like of the shaped article can be made more excellent.

Examples of a preferred cellulose derivative satisfying the conditions as described above include cellulose derivatives represented by the following formulae (12), (13), and (14).

In the formulae (12), (13), and (14), l, m, and n are each independently an integer of 2 or more, q and r each independently an integer of 1 or more, R¹, R², R⁴, and R⁵ are each independently a hydrogen atom (H) or an acetyl group (CH₃CO), and R⁸ is a group represented by the above formula (9).

When the cellulose derivative is a cellulose derivative represented by any of the formulae (12) to (14), the effect as described above is more remarkably exhibited.

It is preferred that the reaction to bond the molecular chains of the cellulose derivative through a covalent bond proceeds by ultraviolet irradiation.

According to this, the productivity of the shaped article can be made more excellent while more effectively preventing undesirable denaturation, deterioration, or the like of the materials. Further, the structure of the production apparatus for the shaped article can be prevented from being complicated, and thus, the production cost of the shaped article can be kept low.

It is preferred that the cellulose derivative (particularly, the cellulose derivative in which the reactive functional group contains a carbon-carbon double bond) reacts with a siloxane compound having two or more S—H bonds in the molecule.

According to this, the efficiency of the formation of the covalent bond can be made more excellent, and thus, the productivity of the shaped article can be made more excellent. In addition, the unreacted cellulose derivative can be effectively prevented from being undesirably contained much in the shaped article. Further, the chemical stability of the covalent bond to be formed by the reaction can be made more excellent. As a result, the durability, strength, and reliability of the shaped article can be made more excellent. Further, the chemical reaction to form the covalent bond by heating can be favorably performed.

The siloxane compound with which the cellulose derivative reacts preferably has two or more S—H bonds in the molecule, but more preferably has three or more S—H bonds in the molecule.

According to this, a more complicated net structure can be formed by the chemical reaction to form the covalent bond, and thus, the durability, strength, and the like of the shaped article can be made more excellent.

The siloxane compound with which the cellulose derivative reacts may be a chain compound, but is preferably a cyclic compound.

According to this, the durability, strength, and the like of the shaped article can be made more excellent.

Examples of the siloxane compound (the siloxane compound which reacts with the cellulose derivative) satisfying such conditions include siloxane compounds represented by the following formula (4).

The cellulose derivative (particularly, the cellulose derivative in which the reactive functional group contains a carbon-carbon double bond) may be a cellulose derivative which reacts with a crosslinking agent.

According to this, a more complicated net structure can be formed by the chemical reaction to form the covalent bond, and thus, the durability, strength, and the like of the shaped article can be made more excellent. Further, for example, by irradiation with a light such as an ultraviolet ray, the chemical reaction to form the covalent bond can be favorably performed.

Examples of the crosslinking agent include compounds having a polymerizable functional group such as a vinyl group or a (meth)acryloyl group.

Among these, a compound having a plurality of polymerizable functional groups in the molecule is preferred, and a compound in which an alkyl chain is modified with a polymerizable functional group at both ends is more preferred.

Examples of such a crosslinking agent include compounds represented by the following formula (5).

In the formula (5), n is an integer of 1 or more.

The weight average molecular weight of the cellulose derivative contained in the liquid composition is not particularly limited, but is preferably 5,000 or more and 10,000,000 or less, more preferably 10,000 or more and 7,000,000 or less.

According to this, the durability, strength, and reliability of the shaped article to be produced can be made more excellent. Further, the storage stability, handleability (for example, the ejection stability by an inkjet method), and the like of the liquid composition can be made excellent.

The content of the cellulosic material in the liquid composition is not particularly limited, but is preferably 30% by mass or more, more preferably 40% by mass or more and 90% by mass or less, further more preferably 45% by mass or more and 85% by mass or less.

According to this, the function intrinsic to the cellulosic material in the shaped article to be produced using the liquid composition is more effectively exhibited, and also the storage stability, handleability (for example, the ejection stability by an inkjet method), and the like of the liquid composition can be made more excellent.

Since the solubility of the cellulosic material in the reactive ionic liquid (which will be described in detail later) is high, in the liquid composition, the cellulosic material is generally present in a state of being dissolved in the reactive ionic liquid, however, may be in a state of being at least partially dispersed in the reactive ionic liquid.

According to such a configuration, the content of the cellulosic material in the liquid composition can be made higher.

Reactive Ionic Liquid

As described above, the liquid composition according to the invention contains an ionic liquid (reactive ionic liquid) having a functional group with reactivity involved in a chemical reaction such as a polymerization reaction in addition to the cellulosic material.

According to this, the cellulosic material can be favorably dissolved in the liquid composition, and the effect as described above can be reliably exhibited.

Examples of a cation constituting the ionic liquid include various cations such as imidazole-based, pyridine-based, alicyclic amine-based, and aliphatic amine-based cations.

Examples of an anion constituting the ionic liquid include various anions such as halogen-based anions (such as bromide anions and triflate anions), boron-based anions (such as tetraphenyl borate anions), and phosphorus-based anions (such as hexafluorophosphate anions).

In particular, the reactive ionic liquid is preferably a reactive ionic liquid having an imidazolium salt structure.

According to this, the solubility of the cellulosic material in the reactive ionic liquid can be made excellent, so that the liquid composition containing the cellulosic material at a higher concentration can be favorably prepared, and thus, a shaped article containing the cellulosic material can be produced with higher dimensional accuracy. Further, when the liquid composition contains a reactive ionic liquid having an imidazolium salt structure, the ejection stability of the liquid composition containing the cellulosic material by an inkjet method or the like can be made more excellent, and therefore, the productivity of the shaped article can be made more excellent.

The functional group with reactivity of the reactive ionic liquid may be a group which directly binds the molecules of the reactive ionic liquid or may be a group which binds the molecules through another atom (at least one atom).

Examples of the functional group (reactive functional group) include a group containing a carbon-carbon double bond, a hydroxy group, and a carboxyl group, however, a group containing a carbon-carbon double bond is preferred.

According to this, the reactivity of the reactive ionic liquid can be made excellent, and the productivity of the shaped article to be produced using the liquid composition can be made more excellent. In addition, the unreacted reactive ionic liquid (in a liquid state) can be effectively prevented from being undesirably contained in the shaped article to be produced. Further, the chemical stability of the covalent bond to be formed by the reaction can be made more excellent. As a result, the durability, strength, and reliability of the shaped article can be made more excellent. Further, the range of choice of a compound which reacts with the reactive ionic liquid (a compound which can react with the reactive functional group of the reactive ionic liquid) is expanded, and thus, the range of design of the reactive ionic liquid is expanded.

Examples of the functional group (reactive functional group) containing a carbon-carbon double bond include a vinyl group and a (meth)acryloyl group, however, a (meth)acryloyl group is preferred.

According to this, the reactivity of the reactive ionic liquid can be made more excellent, and thus, the productivity of the shaped article can be made more excellent. In addition, the unreacted reactive ionic liquid can be more effectively prevented from being undesirably contained in the final shaped article. Further, the chemical stability of the covalent bond to be formed by the reaction can be made more excellent. As a result, the durability, strength, and reliability of the shaped article can be made more excellent. Further, the range of choice of a compound which reacts with the reactive ionic liquid (a compound which can react with the reactive functional group of the reactive ionic liquid) is expanded, and thus, the range of design of the reactive ionic liquid is expanded.

Examples of a preferred reactive ionic liquid satisfying the conditions as described above include ionic liquids represented by the following formula (15).

In the formula (15), n is an integer of 1 or more, and R⁷ is a hydrogen atom (H) or an alkyl group.

When the reactive ionic liquid is an ionic liquid represented by the formula (15), the effect as described above is more remarkably exhibited.

Further, the reactive ionic liquid may be an ionic liquid which reacts with a siloxane compound or the like having two or more S—H bonds in the molecule as described above.

According to this, the same effect as described above is obtained.

It is preferred that the reaction to bond the molecules of the reactive ionic liquid through a covalent bond proceeds by ultraviolet irradiation.

According to this, the productivity of the shaped article can be made more excellent while more effectively preventing undesirable denaturation, deterioration, or the like of the materials. Further, the structure of the production apparatus for the shaped article can be prevented from being complicated, and thus, the production cost of the shaped article can be kept low.

Further, the reactive ionic liquid may at least partially react with the cellulosic material to forma covalent bond between the ionic liquid and the cellulosic material.

The content of the reactive ionic liquid in the liquid composition is not particularly limited, but is preferably 10% by mass or more and 60% by mass or less, more preferably 15% by mass or more and 55% by mass or less.

According to this, for example, the ejection stability and the like of the liquid composition can be made more excellent, and also in the shaped article, while more effectively exhibiting the advantageous characteristics of the cellulosic material, the mechanical strength and the like can be made more excellent.

When the content of the reactive ionic liquid in the liquid composition is represented by Xs (mass %) and the content of the cellulosic material in the liquid composition is represented by Xc (mass %), the liquid composition preferably satisfies the following relationship: 1≦Xc/Xs≦40, more preferably satisfies the following relationship: 1.5≦Xc/Xs≦2.5.

By satisfying such a relationship, the dimensional accuracy, mechanical strength, durability, reliability, and the like of the shaped article to be produced using the liquid composition can be made more excellent while more effectively exhibiting the advantageous characteristics intrinsic to the cellulosic material.

Another Component

The liquid composition may contain a component (another component) other than the above-mentioned components. Examples of such a component include various coloring agents such as a pigment and a dye, various fluorescent materials, various light storage materials, various phosphorescent materials, an infrared absorbing material, a dispersant, a surfactant, a curable resin other than the reactive ionic liquid, a polymerization initiator, a polymerization accelerator, a crosslinking agent, a siloxane compound, a solvent other than the reactive ionic liquid (particularly, a polar solvent such as water), a permeation accelerator, a wetting agent (humectant), a fixing agent, an antifungal agent, a preservative, an antioxidant, an ultraviolet absorbing agent, a chelating agent, a pH adjusting agent, a thickening agent, a filler, an anti-aggregation agent, and a defoaming agent.

Further, by including a coloring agent in the liquid composition, the shaped article colored in a color corresponding to the color of the coloring agent can be obtained.

In particular, by including a pigment as the coloring agent, the light resistance of the liquid composition and the shaped article can be made favorable. As the pigment, either of an inorganic pigment and an organic pigment can be used.

Examples of the inorganic pigment include carbon blacks (C.I. Pigment Black 7) such as Furnace Black, Lamp Black, Acetylene Black, and Channel Black, iron oxide, and titanium oxide, and one pigment or a combination of two or more pigments selected from these can be used.

Among the inorganic pigments described above, in order to take on a preferred white color, titanium oxide is preferred.

Examples of the organic pigment include azo pigments such as insoluble azo pigments, condensed azo pigments, azo lakes, and chelate azo pigments, polycyclic pigments such as phthalocyanine pigments, perylene and perinone pigments, anthraquinone pigments, quinacridone pigments, dioxane pigments, thioindigo pigments, isoindolinone pigments, and quinophthalone pigments, dye chelates (for example, basic dye type chelates, acidic dye type chelates, etc.), dye lakes (basic dye type lakes and acidic dye type lakes), nitro pigments, nitroso pigments, and aniline black, and one pigment or a combination of two or more pigments selected from these can be used.

More specifically, examples of the carbon black to be used as a black pigment include No. 2300, No. 900, MCF88, No. 33, No. 40, No. 45, No. 52, MA7, MA8, MA100, No. 2200B, etc. (all are manufactured by Mitsubishi Chemical Corporation), Raven 5750, Raven 5250, Raven 5000, Raven 3500, Raven 1255, Raven 700, etc. (all are manufactured by Carbon Columbia), Regal 400R, Regal 330R, Regal 660R, Mogul L, Monarch 700, Monarch 800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, Monarch 1400, etc. (all are manufactured by CABOT JAPAN K.K.), and Color Black FW1, Color Black FW2, Color Black FW2V, Color Black FW18, Color Black FW200, Color Black 5150, Color Black 5160, Color Black 5170, Printex 35, Printex U, Printex V, Printex 140U, Special Black 6, Special Black 5, Special Black 4A, Special Black 4, etc. (all are manufactured by Degussa GmbH).

Examples of a white pigment include C.I. Pigment White 6, 18, and 21.

Examples of a yellow pigment include C.I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 16, 17, 24, 34, 35, 37, 53, 55, 65, 73, 74, 75, 81, 83, 93, 94, 95, 97, 98, 99, 108, 109, 110, 113, 114, 117, 120, 124, 128, 129, 133, 138, 139, 147, 151, 153, 154, 167, 172, and 180.

Examples of a magenta pigment include C.I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 40, 41, 42, 48 (Ca), 48 (Mn), 57 (Ca), 57:1, 88, 112, 114, 122, 123, 144, 146, 149, 150, 166, 168, 170, 171, 175, 176, 177, 178, 179, 184, 185, 187, 202, 209, 219, 224, and 245, and C.I. Pigment Violet 19, 23, 32, 33, 36, 38, 43, and 50.

Examples of a cyan pigment include C.I. Pigment Blue 1, 2, 3, 15, 15:1, 15:2, 15:3, 15:34, 15:4, 16, 18, 22, 25, 60, 65, and 66, and C.I. Vat Blue 4 and 60.

Examples of a pigment other than the above-mentioned pigments include C.I. Pigment Green 7 and 10, C.I. Pigment Brown 3, 5, 25, and 26, and C.I. Pigment Orange 1, 2, 5, 7, 13, 14, 15, 16, 24, 34, 36, 38, 40, 43, and 63.

In the case where the liquid composition contains a pigment, the average particle diameter of the pigment is preferably 300 nm or less, more preferably 50 nm or more and 250 nm or less. According to this, for example, the dispersion stability of the pigment in the liquid composition and the ejection stability of the liquid composition can be made more excellent, and also an image with a higher image quality can be formed.

The “average particle diameter” as used herein refers to an average particle diameter on a volume basis and can be determined by, for example, adding a sample to methanol, followed by dispersion for 3 minutes using an ultrasonic disperser, and then, measuring the resulting dispersion liquid using a particle size distribution analyzer employing a Coulter counter method (for example, TA-II, manufactured by Coulter Electronics, Inc.) with an aperture of 50 μm.

Examples of the dye include acidic dyes, direct dyes, reactive dyes, and basic dyes, and one dye or a combination of two or more dyes selected from these can be used.

Specific examples of the dye include C.I. Acid Yellow 17, 23, 42, 44, 79, and 142, C.I. Acid Red 52, 80, 82, 249, 254, and 289, C.I. Acid Blue 9, 45, and 249, C.I. Acid Black 1, 2, 24, and 94, C.I. Food Black 1 and 2, C.I. Direct Yellow 1, 12, 24, 33, 50, 55, 58, 86, 132, 142, 144, and 173, C.I. Direct Red 1, 4, 9, 80, 81, 225, and 227, C.I. Direct Blue 1, 2, 15, 71, 86, 87, 98, 165, 199, and 202, C.I. Direct Black 19, 38, 51, 71, 154, 168, 171, and 195, C.I. Reactive Red 14, 32, 55, 79 and 249, and C.I. Reactive Black 3, 4, and 35.

Examples of the fluorescent material constituting the liquid composition include C.I. Direct Yellow 87, C.I. Acid Red 52, C.I. Acid Red 92, Brilliant Sulfo Flavin, Eosin, Basic Flavin, Acridine Orange, Rhodamine 6G, and Rhodamine B.

Examples of the light storage material constituting the liquid composition include sulfides of alkaline earth metals such as zinc, calcium, strontium, and barium, and light storage materials such as strontium aluminate, or inorganic fluorescent materials such as various sulfides and oxides exemplified as zinc sulfide.

Examples of the phosphorescent material constituting the liquid composition include an iridium complex and a cyclometallated complex.

Examples of the infrared absorbing material constituting the liquid composition include ITO and ATO fine particles.

In the case where the liquid composition contains a dispersoid such as a pigment, if the liquid composition further contains a dispersant, the dispersibility of the dispersoid can be made more favorable.

The dispersant is not particularly limited, but examples thereof include dispersants which are commonly used for preparing a pigment dispersion liquid such as a polymeric dispersant.

Specific examples of the polymeric dispersant include dispersants containing, as a main component, at least one of polyoxyalkylene polyalkylene polyamine, a vinyl-based polymer or copolymer, an acrylic polymer or copolymer, polyester, polyamide, polyimide, polyurethane, an amino-based polymer, a silicon-containing polymer, a sulfur-containing polymer, a fluorine-containing polymer, and an epoxy resin.

Examples of a commercially available product of the polymeric dispersant include AJISPER series manufactured by Ajinomoto Fine-Techno Co., Inc., Solsperse series (Solsperse 36000, etc.) available from Noveon, Inc., DISPERBYK series manufactured by BYK, Inc., and DISPARLON series manufactured by Kusumoto Chemicals, Ltd.

When the liquid composition contains a surfactant, the abrasion resistance of the shaped article can be made more favorable.

The surfactant is not particularly limited, however, for example, a polyester-modified silicone, a polyether-modified silicone, or the like as a silicone-based surfactant can be used, and in particular, it is preferred to use polyether-modified polydimethylsiloxane or polyester-modified polydimethylsiloxane.

Specific examples of the surfactant include BYK-347, BYK-348, BYK-UV 3500, BYK-UV 3510, BYK-UV 3530, and BYK-UV 3570 (all are trade names of products manufactured by BYK, Inc.).

Examples of a curable resin include a thermosetting resin; various photocurable resins such as a visible light curable resin which is cured by a light in the visible light range (a photocurable resin in a narrow sense), a UV curable resin, and an IR curable resin; and an X-ray curable resin, and one curable resin or a combination of two or more curable resins selected from these can be used.

As the UV curable resin (polymerizable compound), a compound whose addition polymerization or ring-opening polymerization is initiated by a radical species, a cationic species, or the like generated from a photopolymerization initiator by ultraviolet irradiation, thereby forming a polymer is preferably used. Examples of the polymerization form of the addition polymerization include radical, cationic, anionic, metathesis, and coordination polymerization. Further, examples of the polymerization form of the ring-opening polymerization include cationic, anionic, radical, metathesis, and coordination polymerization.

Examples of an addition polymerizable compound include compounds having at least one ethylenically unsaturated double bond. As the addition polymerizable compound, a compound having at least one, preferably two or more terminal ethylenically unsaturated bonds can be preferably used.

An ethylenically unsaturated polymerizable compound has a chemical form of a monofunctional polymerizable compound, a polyfunctional polymerizable compound, or a mixture thereof.

Examples of the monofunctional polymerizable compound include unsaturated carboxylic acids (for example, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, etc.) and esters thereof, and amides thereof.

As the polyfunctional polymerizable compound, an ester of an unsaturated carboxylic acid with an aliphatic polyhydric alcohol compound or an amide of an unsaturated carboxylic acid with an aliphatic amine compound is used.

Further, an addition reaction product of an ester or an amide of an unsaturated carboxylic acid having a hydroxyl group or a nucleophilic substituent such as an amino group or a mercapto group with an isocyanate or an epoxy, a dehydration condensation reaction product with a carboxylic acid, or the like can also be used. Further, an addition reaction product of an ester or an amide of an unsaturated carboxylic acid having an electrophilic substituent such as an isocyanate group or an epoxy group with an alcohol, an amine, or a thiol, further, a substitution reaction product of an ester or an amide of an unsaturated carboxylic acid having a leaving substituent such as a halogen group or a tosyloxy group with an alcohol, an amine, or a thiol can also be used.

As a specific example of the radical polymerizable compound which is the ester of an unsaturated carboxylic acid with an aliphatic polyhydric alcohol compound, for example, a (meth)acrylate ester is representative, and either a monofunctional(meth)acrylate or a polyfunctional(meth)acrylate can be used.

Specific examples of the monofunctional(meth)acrylate include tolyloxyethyl(meth)acrylate, phenyloxyethyl(meth)acrylate, cyclohexyl(meth)acrylate, ethyl(meth)acrylate, methyl(meth)acrylate, isobornyl(meth)acrylate, dipropylene glycol di(meth)acrylate, tetrahydrofurfuryl(meth)acrylate, ethoxyethoxyethyl(meth)acrylate, 2-(2-vinyloxyethoxy)ethyl(meth)acrylate, 2-hydroxy-3-phenoxypropyl(meth)acrylate, and 4-hydroxybutyl(meth)acrylate.

Specific examples of a difunctional (meth)acrylate include ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, tetramethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, hexanediol di(meth)acrylate, 1,4-cyclohexanediol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, and dipentaerythritol di(meth)acrylate.

Specific examples of a trifunctional(meth)acrylate include trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, alkylene oxide-modified tri(meth)acrylate of trimethylolpropane, pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, trimethylolpropane tri((meth)acryloyloxypropyl) ether, isocyanuric acid alkylene oxide-modified tri(meth)acrylate, propionic acid dipentaerythritol tri(meth)acrylate, tri((meth)acryloyloxyethyl) isocyanurate, hydroxypivalaldehyde-modified dimethylolpropane tri(meth)acrylate, and sorbitol tri(meth)acrylate.

Specific examples of a tetrafunctional(meth)acrylate include pentaerythritol tetra(meth)acrylate, sorbitol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, propionic acid dipentaerythritol tetra(meth)acrylate, and ethoxylated pentaerythritol tetra(meth)acrylate.

Specific examples of a pentafunctional (meth)acrylate include sorbitol penta(meth)acrylate and dipentaerythritol penta(meth)acrylate.

Specific examples of a hexafunctional (meth)acrylate include dipentaerythritol hexa(meth)acrylate, sorbitol hexa(meth)acrylate, alkylene oxide-modified hexa(meth)acrylate of phosphazene, and caprolactone-modified dipentaerythritol hexa(meth)acrylate.

Examples of the polymerizable compound other than (meth)acrylates include itaconate esters, crotonate esters, isocrotonate esters, and maleate esters.

Examples of the itaconate esters include ethylene glycol diitaconate, propylene glycol diitaconate, 1,3-butanediol diitaconate, 1,4-butanediol diitaconate, tetramethylene glycol diitaconate, pentaerythritol diitaconate, and sorbitol tetraitaconate.

Examples of the crotonate esters include ethylene glycol dicrotonate, tetramethylene glycol dicrotonate, pentaerythritol dicrotonate, and sorbitol tetradicrotonate.

Examples of the isocrotonate esters include ethylene glycol diisocrotonate, pentaerythritol diisocrotonate, and sorbitol tetraisocrotonate.

Examples of the maleate esters include ethylene glycol dimaleate, triethylene glycol dimaleate, pentaerythritol dimaleate, and sorbitol tetramaleate.

As an example of another ester, for example, an aliphatic alcohol ester, an ester having an aromatic backbone, an ester containing an amino group, or the like can also be used.

Specific examples of a monomer of the amide of an unsaturated carboxylic acid with an aliphatic amine compound include methylenebis-acrylamide, methylenebis-methacrylamide, 1,6-hexamethylenebis-acrylamide, 1,6-hexamethylenebis-methacrylamide, diethylenetriamine trisacrylamide, xylylene bisacrylamide, xylylene bismethacrylamide, and (meth)acryloylmorpholine.

Other preferred examples of an amide-based monomer include monomers having a cyclohexylene structure.

A urethane-based addition polymerizable compound which is produced by an addition reaction between an isocyanate and a hydroxy group is also preferred, and specific examples of such a compound include vinyl urethane compounds containing two or more polymerizable vinyl groups in one molecule obtained by adding a vinyl monomer containing a hydroxy group represented by the following formula (1) to a polyisocyanate compound having two or more isocyanate groups in one molecule. CH₂═C(R¹)COOCH₂CH(R²)OH  (1)

In the formula (1), R¹ and R² each independently represent H or CH₃.

In the invention, a cationic ring-opening polymerizable compound having at least one cyclic ether group such as an epoxy group or an oxetane group in the molecule can be favorably used as a UV curable resin (polymerizable compound).

Examples of the cationic polymerizable compound include curable compounds containing a ring-opening polymerizable group, and among these, heterocyclic group-containing curable compounds are more preferred. Examples of such curable compounds include cyclic imino ethers such as epoxy derivatives, oxetane derivatives, tetrahydrofuran derivatives, cyclic lactone derivatives, cyclic carbonate derivatives, and oxazoline derivatives, and vinyl ethers, and among these, epoxy derivatives, oxetane derivatives, and vinyl ethers are preferred.

Preferred examples of the epoxy derivatives include monofunctional glycidyl ethers, polyfunctional glycidyl ethers, monofunctional alicyclic epoxies, and polyfunctional alicyclic epoxies.

Specific examples of compounds of the glycidyl ethers include diglycidyl ethers, (for example, ethylene glycol diglycidyl ether, bisphenol A diglycidyl ether, etc.), trifunctional or higher functional glycidyl ethers (for example, trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether, glycerol triglycidyl ether, triglycidyl trishydroxyethyl isocyanurate, etc.), tetrafunctional or higher functional glycidyl ethers (for example, sorbitol tetraglycidyl ether, pentaerythritol tetraglycyl ether, polyglycidyl ethers of cresol novolac resins, polyglycidyl ethers of phenolnovolac resins, etc.), alicyclic epoxies (for example, Celloxide 2021P, Celloxide 2081, Epolead GT-301, and Epolead GT-401 (all are manufactured by Daicel Chemical Industries, Ltd.)), EHPE (manufactured by Daicel Chemical Industries, Ltd.), polycyclohexyl epoxy methyl ethers of phenol novolac resins, etc.), and oxetanes (for example, OX-SQ and PNOX-1009 (all are manufactured by Toagosei Co., Ltd.), etc.).

As the polymerizable compound, an alicyclic epoxy derivative can be preferably used. An “alicyclic epoxy group” refers to a partial structure in which a double bond of a cycloalkene ring of a cyclopentene group, a cyclohexene group, or the like is epoxidized with a suitable oxidizing agent such as hydrogen peroxide or a peroxy acid.

As the alicyclic epoxy compound, a polyfunctional alicyclic epoxy compound having two or more cyclohexene oxide groups or cyclopentene oxide groups in one molecule is preferred. Specific examples of the alicyclic epoxy compound include 4-vinylcyclohexene dioxide, (3,4-epoxycyclohexyl)methyl-3,4-epoxycyclohexylcarboxylate, di(3,4-epoxycyclohexyl) adipate, di(3,4-epoxycyclohexylmethyl) adipate, bis(2,3-epoxycyclopentyl) ether, di(2,3-epoxy-6-methylcyclohexylmethyl) adipate, and dicyclopentadiene dioxide.

A normal glycidyl compound having an epoxy group but having no alicyclic structure in the molecule can be used alone or can also be used in combination with the above-mentioned alicyclic epoxy compound.

Examples of such a normal glycidyl compound include a glycidyl ether compound and a glycidyl ester compound, but it is preferred to use a glycidyl ether compound in combination.

Specific examples of the glycidyl ether compound include aromatic glycidyl ether compounds such as 1,3-bis(2,3-epoxypropyloxy)benzene, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a phenol novolac type epoxy resin, a cresol novolac type epoxy resin, and a trisphenol methane type epoxy resin; and aliphatic glycidyl ether compounds such as 1,4-butanediol glycidyl ether, glycerol triglycidyl ether, propylene glycol diglycidyl ether, and trimethylolpropane tritriglycidyl ether. Examples of the glycidyl ester include glycidyl esters of linoleic acid dimers.

As the polymerizable compound, a compound having an oxetanyl group, which is a four-membered cyclic ether (hereinafter also simply referred to as “oxetane compound”), can be used. The oxetanyl group-containing compound is a compound having one or more oxetanyl groups in one molecule.

As the polymerization initiator, for example, azobisisobutyronitrile (AIBN), bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, or the like can be used.

The liquid composition may be any as long as it has fluidity and may be in the form of, for example, a paste, however, the viscosity of the liquid composition is preferably 2 mPa·s or more and 30 mPa·s or less, more preferably 5 mPa·s or more and 20 mPa·s or less.

According to this, the ejection stability of the liquid composition by, for example, an inkjet method can be made more excellent.

The “viscosity” as used herein refers to a value obtained by measurement at 25° C. using an E-type viscometer (for example, VISCONIC ELD, manufactured by Tokyo Keiki, Inc.).

Shaped Article

Next, the shaped article (three-dimensionally shaped article) according to the invention will be described.

The shaped article according to the invention is produced using the liquid composition according to the invention as described above.

According to this, the shaped article which contains the cellulosic material and has excellent dimensional accuracy and strength can be provided.

The shaped article according to the invention has such excellent characteristics, and therefore can be applied to various uses.

The use of the shaped article according to the invention is not particularly limited, however, examples of the use include ornaments and exhibits such as dolls and figures; medical devices such as artificial dialyzers and implants; printing papers; optical members such as lenses (including variable focus lenses), phase difference films, and polarizing plates; gel materials such as culture scaffold materials to be used for cultivation of various cells, various bacteria, etc.; vehicles such as bicycles; nursing care goods such as wheelchairs, and the like, and constituent components thereof, and the like.

Further, the shaped article according to the invention may be applied to any of prototypes, mass-produced products, and custom-made products.

Shaped Article Production Method

Next, a shaped article production method according to the invention will be described.

The shaped article according to the invention may be any as long as it is produced using the liquid composition according to the invention as described above, and the production method for the shaped article is not particularly limited.

Examples of the shaped article production method according to the invention include various molding methods such as compression molding, extrusion molding, and injection molding, and methods for subjecting a bulk material to a machining process such as cutting, grinding, or polishing.

Further, as the shaped article production method according to the invention, a three-dimensional shaping method (a method for producing a three-dimensionally shaped article by performing a layer forming step of forming a layer using a composition a plurality of times and stacking the layers on one another) as described below can be used.

According to this, even a shaped article required to have high dimensional accuracy or a shaped article having a complicated shape can be efficiently produced with sufficient dimensional accuracy. Further, the production method can be favorably applied also to the production of a plurality of types of shaped articles having different shapes and sizes.

Hereinafter, a case where a three-dimensional shaping method is applied will be described as a specific example of the shaped article production method.

First Embodiment

FIGS. 1A to 1H are cross-sectional views schematically showing respective steps in a first embodiment of the shaped article production method according to the invention.

As shown in FIGS. 1A to 1H, the production method of this embodiment is configured as follows. The method includes a layer forming step (FIGS. 1A and 1D) in which a layer P1 having a given thickness is formed in a region surrounded by a side surface support part (frame body) 45 using a composition containing particles P1′, a liquid composition application step (FIGS. 1B and 1E) in which a liquid composition (ink) P12 containing a cellulosic material and a reactive ionic liquid is applied to the layer P1 by an inkjet method, and a solidification step (FIGS. 1C and 1F) in which the reactive components contained in the liquid composition P12 applied to the layer P1 is solidified (cured). These steps are sequentially and repeatedly performed (FIG. 1G), and thereafter, the method further includes an unbound particle removal step (FIG. 1H) in which among the particles constituting the respective layers P1, the particles which are not bound to one another by the liquid composition (binder) are removed.

Hereinafter, the respective steps will be described.

Layer Forming Step

In the layer forming step, a layer P1 having a given thickness is formed using a composition containing particles (particle-containing composition) P1′ (FIGS. 1A and 1D).

In this manner, by using the composition containing particles P1′, the dimensional accuracy of a shaped article (three-dimensionally shaped article) P10 to be obtained finally can be made excellent. Further, the heat resistance, mechanical strength, and the like of the shaped article P10 can be made more excellent.

The composition P1′ will be described in detail later.

In this step, by using a flattening unit, the layer P1 is formed such that the surface is flattened.

In the first layer forming step, the layer P1 is formed to a given thickness on the surface of a stage 41 (FIG. 1A). At this time, the side surface of the stage 41 and the side surface support part 45 are in a close contact (abutment) state, so that the composition P1′ is prevented from falling between the stage 41 and the side surface support part 45.

In each of the second and subsequent layer forming steps, a new layer P1 (second layer) is formed on the surface of the layer P1 (first layer) formed in the previous step (FIG. 1D). At this time, the side surface of the layer P1 on the stage 41 (in the case where a plurality of layers P1 are present on the stage 41, at least the layer P1 provided on the uppermost side) and the side surface support part 45 are in a close contact (abutment) state, so that the composition P1′ is prevented from falling between the stage 41 and the layer P1 on the stage 41.

In this step, the composition P1′ may be heated. By doing this, for example, in the case where the composition P1′ contains a molten component, the composition P1′ can be more favorably transformed into a paste.

The viscosity of the composition P1′ in this step is preferably 500 mPa·s or more and 1,000,000 mPa·s or less. According to this, the occurrence of an undesirable variation in the film thickness of the layer P1 to be formed can be more effectively prevented.

The thickness of the layer P1 to be formed in this step is not particularly limited, but is, for example, preferably 20 μm or more and 500 μm or less, more preferably 30 μm or more and 150 μm or less. According to this, while making the productivity of the shaped article P10 sufficiently excellent, the occurrence of undesirable irregularities or the like in the shaped article P10 to be produced is more effectively prevented, and the dimensional accuracy of the shaped article P10 can be made more excellent.

Liquid Composition Application Step (Ink Application Step)

After the layer P1 is formed in the layer forming step, a liquid composition (ink) P12 containing a cellulosic material and a reactive ionic liquid is applied to the layer P1 by an inkjet method (FIGS. 1B and 1E).

The liquid composition P12 contains a reactive ionic liquid having excellent solubility of the cellulosic material, and therefore contains the cellulosic material uniformly. According to this, the liquid composition P12 has excellent fluidity, and thus, only a desired amount of the liquid composition can be supplied to a desired region.

In this step, the liquid composition P12 is selectively applied only to a region corresponding to a tangible part (a region where a tangible body is present) of the shaped article P10 to be produced in the layer P1.

By doing this, the particles constituting the layer P1 are bound to one another, whereby a bound part (tangible part) P13 having a desired shape can be formed in the end.

In this step, the liquid composition P12 is applied by an inkjet method, and therefore, even if a pattern in which the liquid composition P12 is applied has a finer shape, the liquid composition P12 can be applied with higher reproducibility. As a result, the dimensional accuracy of the finally obtained shaped article P10 can be made higher. Further, in the related art, in the case where a shaped article constituted by a material containing a cellulosic material is tried to be produced using an inkjet method, a problem that the dimensional accuracy or the like of the shaped article is low occurred more remarkably. However, according to the invention, even in the case where an inkjet method is used, the occurrence of such a problem can be reliably prevented. That is, in the case where the liquid composition is applied using an inkjet method, the effect of the invention is more remarkably exhibited.

The liquid composition P12 may be applied onto a member having been subjected to an alignment treatment. That is, the stage 41 may have a surface having been subjected to an alignment treatment.

According to this, in the case where the cellulose derivative contained in the liquid composition P12 has a liquid crystalline moiety, the cellulose derivative (liquid crystalline moiety) can be more favorably aligned, and thus, the mechanical strength, durability, reliability, and the like of the finally obtained shaped article P10 can be made more excellent.

In the case where the surface of the stage 41 has been subjected to an alignment treatment, also in the second and subsequent layers P1, in a region to which the liquid composition P12 is applied, the cellulose derivative (liquid crystalline moiety) is affected by each layer P1 immediately thereunder (the layer P1 in which the cellulose derivative (liquid crystalline moiety) is aligned), and therefore, even if the layer is not in direct contact with the stage, the cellulose derivative (liquid crystalline moiety) is favorably aligned. That is, for the second and subsequent layers P1, each layer P1 immediately thereunder functions as a member having been subjected to an alignment treatment.

As the alignment treatment, a method such as a rubbing treatment is favorably used.

Further, as a material of the surface of the stage 41, for example, a material which is favorably subjected to an alignment treatment such as polyimide can be used.

Solidification Step (Curing Step)

After the liquid composition P12 is applied to the layer P1 in the liquid composition application step, the liquid composition P12 is solidified (cured), whereby a bound part (tangible part) P13 is formed (FIGS. 1C and 1F).

In this manner, the liquid composition P12 loses its fluidity, and the bound part (tangible part) P13 is formed (FIGS. 1C and 1F).

In this step, at least a chemical reaction (a chemical reaction to form a covalent bond) involving the reactive ionic liquid is performed. According to this, the hardness of the bound part (tangible part) P13 to be formed can be increased, and thus, the mechanical strength, durability, and reliability of the finally obtained shaped article P10 can be made excellent.

Further, in the case where the liquid composition P12 contains a cellulose derivative having a reactive functional group, a chemical reaction (a chemical reaction to form a covalent bond) involving the cellulose derivative may be performed. According to this, the hardness of the bound part (tangible part) P13 to be formed can be increased, and thus, the mechanical strength, durability, and reliability of the finally obtained shaped article P10 can be made excellent.

In this step, in the case where a chemical reaction to form a covalent bond (curing reaction) is performed, the chemical reaction can be performed by, for example, heating, irradiation with an energy ray (for example, a ray such as an ultraviolet ray, an electron beam, a positron beam, a neutron beam, an α beam, an ion beam, etc.), or the like.

In particular, in the case where the chemical reaction is allowed to proceed by heating, the structure of the production apparatus for the shaped article P10 can be simplified. Further, even if the starting material of the shaped article P10 is a material having a low light transmittance, a desired reaction can be allowed to favorably proceed.

In the case where the chemical reaction is allowed to proceed by heating, the heating temperature is preferably 50° C. or higher and 180° C. or lower, more preferably 60° C. or higher and 150° C. or lower.

Further, in the case where the chemical reaction is allowed to proceed by light irradiation, the productivity of the shaped article P10 can be made more excellent while more effectively preventing undesirable denaturation, deterioration, or the like of the materials.

In the case where the chemical reaction is allowed to proceed by light irradiation, as the light, for example, an ultraviolet ray, an infrared ray, a visible light, an X-ray, a microwave, a radio wave, or the like can be used, however, it is preferred to use an ultraviolet ray.

According to this, the productivity of the shaped article P10 can be made more excellent, and also the structure of the production apparatus for the shaped article P10 can be prevented from being complicated, and thus, the production cost of the shaped article P10 can be kept low.

Further, in the case where the chemical reaction is allowed to proceed by ultraviolet irradiation, the peak wavelength of the ultraviolet ray is preferably 250 nm or more and 400 nm or less. Further, the ultraviolet irradiation time for each region to be cured is preferably 30 seconds or more and 60 seconds or less.

The liquid composition application step and the solidification step may be performed in a parallel manner. That is, before forming the entire pattern of the entire one layer P1, the reaction may be allowed to sequentially proceed from a region to which the liquid composition P12 is applied.

Unbound Particle Removal Step

After the steps as described above are performed repeatedly, as a post-treatment step, an unbound particle removal step (FIG. 1H) in which among the particles constituting the respective layers P1, the particles which are not bound to one another by the liquid composition P12 (unbound particles) are removed is performed. By doing this, the shaped article P10 is taken out.

Examples of a specific method of this step include a method in which the unbound particles are removed by brushing with a brush or the like, a method in which the unbound particles are removed by suction, a method in which a gas such as air is blown, a method in which a liquid such as water is applied (for example, a method in which a stacked body obtained as described above is soaked in a liquid, a method in which a liquid is blown, etc.), and a method in which vibration such as ultrasonic vibration is applied. Further, two or more methods selected from these methods can be performed in combination. More specifically, a method in which a gas such as air is blown to the stacked body, and thereafter, the stacked body is soaked in a liquid such as water, a method in which ultrasonic vibration is applied to the stacked body while soaking the stacked body in a liquid such as water, and the like can be exemplified. Above all, it is preferred to adopt a method in which a liquid containing water is applied to the stacked body obtained as described above (particularly, a method in which the stacked body is soaked in a liquid containing water).

Second Embodiment

Next, a second embodiment of the shaped article production method will be described.

FIGS. 2A to 2F are cross-sectional views schematically showing respective steps in a second embodiment of the shaped article production method according to the invention. In the following description, different points from the above-mentioned embodiment will be mainly described, and the description of the same matter will be omitted.

As shown in FIGS. 2A to 2F, the production method of this embodiment is configured as follows. The method includes an ink application step (FIGS. 2A and 2C) in which a tangible part forming ink P16′ serving as the liquid composition which contains a cellulosic material and a reactive ionic liquid and is used for forming a tangible part P16 and a support part forming ink P17′ which is used for forming a support part P17 for supporting the tangible part P16 are ejected in a given pattern by an inkjet method, and a solidification step (FIGS. 2B and 2D) in which the ejected tangible part forming ink P16′ and support part forming ink P17′ are solidified (cured), thereby forming the tangible part P16 and the support part P17. These steps are sequentially and repeatedly performed, thereby obtaining a preform body P10′ (FIG. 2E), and thereafter, the method further includes a support part removal step (FIG. 2F) in which the support part P17 is removed.

In this manner, in this embodiment, by the ink application step and the solidification step (curing step), the layer P1 is formed. That is, in this embodiment, a layer forming step includes the ink application step and the solidification step.

In this manner, in this embodiment, the layer is formed using the ink to be ejected by an inkjet method as the composition for forming the layer without forming a layer while flattening the composition containing particles by a flattening unit.

According to this, the composition can be selectively applied to a necessary place in a shaping region (a region on a stage 41), and therefore, the wasting of the material in the production of the shaped article P10 can be prevented and suppressed. Due to this, this is advantageous from the viewpoint of reduction in the production cost of the shaped article P10 and resource saving. Further, the number of steps can be reduced as a whole, and also a treatment such as recovery of the material or the like can be omitted or simplified, and thus, the productivity of the shaped article P10 can be made more excellent.

Hereinafter, the respective steps will be described.

Ink Application Step (Ink Ejection Step)

In the ink application step, a tangible part forming ink P16′ serving as the liquid composition which contains a cellulosic material and a reactive ionic liquid and a support part forming ink P17′ which contains a curable resin (curable component) are ejected in a given pattern by an inkjet method (FIGS. 2A and 2C).

More specifically, the tangible part forming ink P16′ is applied to a region which is to become the tangible part P16 of the shaped article (three-dimensionally shaped article) P10, and the support part forming ink P17′ is applied to a region which is adjacent to a region to become the outermost layer of the tangible part P16 of the shaped article P10 and on the surface side of the outermost layer.

In the first ink application step, on the stage 41, the inks (the tangible part forming ink P16′ and the support part forming ink P17′) are ejected (FIG. 2A), and in each of the second and subsequent ink application steps, on the layer P1, the inks (the tangible part forming ink P16′ and the support part forming ink P17′) are ejected (FIG. 2C).

In this manner, in this embodiment, not only the liquid composition (the tangible part forming ink P16′) is applied to the region which is to become the tangible part P16 of the shaped article P10, but also the ink (the support part forming ink P17′) is applied to the surface side thereof.

According to this, by forming the support part P17 by applying the support part forming ink P17′, even if a layer constituting the shaped article P10 (second layer) has a portion protruding from the outer peripheral portion of the layer (first layer) lower than this layer (for example, in the drawing, a relationship between the first layer and the second layer from the bottom, a relationship between the second layer and the third layer from the bottom, a relationship between the fifth layer and the sixth layer from the bottom, and a relationship between the sixth layer and the seventh layer from the bottom), the support part P17 as the lower layer (first layer) can favorably support the tangible part forming ink P16′ for forming the upper layer (second layer). Due to this, undesirable deformation (particularly, sagging or the like) of the tangible part P16 can be favorably prevented, and thus, the dimensional accuracy of the finally obtained shaped article P10 can be made more excellent.

Further, in this step, the inks (the tangible part forming ink P16′ and the support part forming ink P17′) are applied by an inkjet method, and therefore, even if the pattern in which the inks (the tangible part forming ink P16′ and the support part forming ink P17′) are applied has a fine shape, the inks can be applied with high reproducibility. As a result, the dimensional accuracy of the finally obtained shaped article P10 can be made higher, and also the control of the surface shape and appearance of the shaped article P10 can be more favorably performed.

The support part forming ink P17′ will be described in detail later.

The amount of the ink to be applied in this step is not particularly limited, but is preferably such that the thickness of the layer P1 to be formed in the subsequent solidification step becomes 30 μm or more and 500 μm or less, more preferably 70 μm or more and 150 μm or less.

According to this, while sufficiently enhancing the productivity of the shaped article P10, the occurrence of undesirable irregularities or the like in the shaped article P10 to be produced is more effectively prevented, and the dimensional accuracy of the shaped article P10 can be made more excellent. In addition, the surface state and appearance of the finally obtained shaped article P10 can be more favorably controlled.

Solidification Step (Layer Forming Step)

After the inks (the tangible part forming ink P16′ and the support part forming ink P17′) are applied (ejected) in the ink application step, the tangible part forming ink P16′ is solidified (cured) and also the curable component (curable resin) contained in the support part forming ink P17′ is cured (FIGS. 2B and 2D). By doing this, the layer P1 having the tangible part P16 and the support part P17 is obtained. That is, the region to which the tangible part forming ink P16′ is applied becomes the tangible part P16, and the region to which the support part forming ink P17′ is applied becomes the support part P17.

This step can be performed by, for example, heating, irradiation with an energy ray (for example, a ray such as an ultraviolet ray, an electron beam, a positron beam, a neutron beam, an α beam, an ion beam, etc.), or the like, although the method varies depending on the constituent material of the tangible part forming ink P16′ and the type of the curable component (curable resin) contained in the support part forming ink P17′.

In particular, in the case where the tangible part P16 and the support part P17 are formed by heating, the structure of the production apparatus for the shaped article P10 can be simplified. Further, even if the starting material of the shaped article P10 is a material having a low light transmittance, a desired reaction can be allowed to favorably proceed.

In the case where the tangible part P16 and the support part P17 are formed by heating, the heating temperature is preferably 50° C. or higher and 180° C. or lower, more preferably 60° C. or higher and 150° C. or lower.

Further, in the case where the tangible part P16 and the support part P17 are formed by light irradiation, the productivity of the shaped article P10 can be made more excellent while more effectively preventing undesirable denaturation, deterioration, or the like of the materials.

In the case where the tangible part P16 and the support part P17 are formed by light irradiation, as the light, for example, an ultraviolet ray, an infrared ray, a visible light, an X-ray, a microwave, a radio wave, or the like can be used, however, it is preferred to use an ultraviolet ray.

According to this, the productivity of the shaped article P10 can be made more excellent, and also the structure of the production apparatus for the shaped article P10 can be prevented from being complicated, and thus, the production cost of the shaped article P10 can be kept low.

In the above explanation, it is described that the inks are applied in a shape and a pattern corresponding to the layer P1 and thereafter the entire layer (the layer corresponding to the layer P1) constituted by the inks is cured, however, in the invention, in at least a partial region, the ejection of the ink and the curing of the ink may be performed in a parallel manner. That is, before forming the entire pattern of the entire one layer P1, a curing reaction may be allowed to sequentially proceed from a region to which the ink is applied in at least part of the region corresponding to the layer P1. However, for at least a contact portion between the tangible part forming ink P16′ and the support part forming ink P17′ (a portion where the tangible part P16 and the support part P17 should be in contact with each other), the curing treatment is performed simultaneously, and the curing treatment for the tangible part forming ink P16′ and the curing treatment for the support part forming ink P17′ are not performed separately.

In this step, it is not necessary to completely cure the curable component contained in the ink. For example, at the end of this step, the support part forming ink P17′ may be in an incompletely cured state and the tangible part forming ink P16′ may be cured to a higher curing degree than the support part forming ink P17′.

According to this, the support part removal step, which will be described in detail later, can be easily performed, and the productivity of the shaped article P10 can be further improved.

Further, at the end of this step, the tangible part forming ink P16′ may be brought to a state where the tangible part forming ink P16′ is cured in an incomplete state. Even in such a case, for example, after performing a subsequent step (for example, the “ink application step” or the like after forming the layer P1 on the lower side in the solidification step (curing step)), by performing a main curing treatment for increasing the curing degree of the tangible part forming ink P16′ (tangible part P16) in an incompletely cured state, the mechanical strength and the like of the finally obtained shaped article P10 can be made excellent. Further, by applying the ink for forming the upper layer in a state where the tangible part forming ink P16′ (lower layer) is cured in an incomplete state, the adhesiveness between the layers can be made more excellent.

Support Part Removal Step

After a series of steps as described above are performed repeatedly, the support part P17 is removed (FIG. 2F). By doing this, the shaped article P10 is obtained.

Examples of a method for removing the support part P17 include a method in which the support part P17 is selectively dissolved and removed using a liquid which selectively dissolves the support part P17, and a method in which a liquid for which the support part P17 has higher absorbability than the tangible part P16 is used and the support part P17 is made to selectively absorb the liquid to swell the support part P17, or to decrease the mechanical strength of the support part P17, and then, the support part P17 is exfoliated or disrupted.

The liquid to be used in this step varies depending on the constituent materials or the like of the tangible part P16 and the support part P17, however, examples thereof include water, alcohols such as methanol, ethanol, isopropyl alcohol, n-propyl alcohol, butanol, and isobutanol, glycerin, and glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, and dipropylene glycol, and one liquid or a combination of two or more liquids selected from these can be used. Further, the liquid may be a liquid mixed with a water-soluble substance which generates a hydroxide ion such as sodium hydroxide, potassium hydroxide, sodium hydrogen carbonate, or an organic amine for increasing the solubility of the support part, a surfactant which facilitates the separation of the exfoliated support part, or the like. The liquid as described above has high polarity and also has excellent compatibility with the reactive ionic liquid (unreacted reactive ionic liquid). Therefore, in the case where the unreacted reactive ionic liquid is undesirably contained in the tangible part P16 before this step, by using the liquid as described above, the unreacted reactive ionic liquid can be efficiently removed, and thus, the unreacted reactive ionic liquid can be effectively prevented from remaining in the finally obtained shaped article P10.

A method for applying the liquid to the preform body P10′ is not particularly limited, and for example, a soaking method, a spraying method, a coating method, a variety of printing methods, and the like can be adopted.

In the above explanation, it is described that the liquid is used in the step, however, a substance having the same function (for example, a solid, a gas, a supercritical fluid, or the like) may be used.

Further, when or after the liquid is applied, ultrasonic vibration may be applied.

By doing this, the removal of the support part P17 can be accelerated, and thus, the productivity of the shaped article P10 can be made more excellent.

In the above explanation, it is described that the support part forming ink P17′ is applied so as to come in contact with the tangible part forming ink P16′ in the entire region which is to become the outermost layer of the shaped article P10, however, the support part forming ink P17′ may be applied so as to come in contact with the tangible part forming ink P16′ only in a portion of the region which is to become the outermost layer of the shaped article P10. Further, in the case where the shaped article P10 to be produced has a shape which can be produced without forming the support part P17, the support part forming ink P17′ may not be used.

In the case where the formation of the support part is not needed due to the shape or the like of the shaped article P10 to be produced, the layer P1 may be formed using only the tangible part forming ink.

Incidentally, in the production of the shaped article, a plurality of types of liquid compositions containing a cellulosic material and a reactive ionic liquid as described above may be used.

For example, a liquid composition as an ink (color ink) which contains a coloring agent and a liquid composition as an ink (clear ink) which does not contain a coloring agent may be used. According to this, for example, as a liquid composition to be applied to a region which has an effect on the color tone in appearance of the shaped article P10, a liquid composition which contains a coloring agent is used, and as a liquid composition to be applied to a region which does not have an effect on the color tone in appearance of the shaped article P10, a liquid composition which does not contain a coloring agent can be used.

In addition, for example, a plurality of types of liquid compositions which contain a coloring agent having a different composition may be used. According to this, by using these liquid compositions in combination, an expressible color reproduction range can be expanded.

In the case where a plurality of types of liquid compositions (inks) are used, it is preferred to use at least a cyan ink, a magenta ink, and a yellow ink. According to this, by using these liquid compositions in combination, an expressible color reproduction range can be further expanded.

Further, for example, by using a plurality of types of liquid compositions (inks) having different types or contents of the cellulosic material or the reactive ionic liquid, the properties such as rigidity and elasticity required for individual regions of the shaped article P10 can be favorably adjusted.

Shaped Article Production Apparatus

Next, a production apparatus (a shaped article production apparatus) which can be used for producing the shaped article (three-dimensionally shaped article) according to the invention will be described.

First Embodiment

FIG. 3 is a cross-sectional view schematically showing a first embodiment of the production apparatus to be used for producing the shaped article according to the invention.

A shaped article production apparatus 100 shown in FIG. 3 produces a shaped article P10 by repeatedly forming a layer P1 using a composition containing particles (particle-containing composition) P1′, and stacking the formed layers P1.

As shown in FIG. 3, the shaped article production apparatus 100 includes a control section 2, a composition supply section (particle-containing composition supply section) 3 which supplies the composition containing particles P1′, a layer forming section 4 which forms the layer P1 using the composition P1′ supplied from the composition supply section 3, a liquid composition ejection section (liquid composition application unit) 5 which ejects the liquid composition (ink) P12 to the layer P1, and an energy ray irradiation unit (solidification unit or bond forming unit) 6 which irradiates an energy ray for solidifying (curing) the liquid composition P12.

The control section 2 includes a computer 21 and a drive control section 22.

The computer 21 is a common desk top computer or the like configured to include a CPU, a memory, etc. therein. The computer 21 digitizes the shape of the shaped article (three-dimensionally shaped article) P10 as model data, and outputs cross-sectional data (slice data) obtained by slicing the shaped article P10 into a plurality of parallel layers of thin cross sections to the drive control section 22.

The drive control section 22 functions as a control unit for individually driving the layer forming section 4, the liquid composition ejection section 5, and the energy ray irradiation unit 6. Specifically, for example, the drive control section 22 controls the ejection pattern and the ejection amount of the liquid composition P12 by the liquid composition ejection section 5, the supply amount of the composition P1′ from the composition supply section 3, the descent amount of a stage 41, and the like.

The composition supply section 3 is configured to move under the command of the drive control section 22 and supply the composition P1′ stored therein to a composition temporary placing section 44.

The layer forming section 4 includes the composition temporary placing section 44 which temporarily holds the composition P1′ supplied from the composition supply section 3, a squeegee (flattening unit) 42 which forms a layer P1 while flattening the composition P1′ held by the composition temporary placing section 44, a guide rail 43 which regulates the movement of the squeegee 42, the stage 41 which supports the formed layer P1, and a side surface support section (frame body) 45 which surrounds the stage 41.

When a new layer P1 is formed on a previously formed layer P1, the previously formed layer P1 is moved relatively downward with respect to the side surface support section 45. By doing this, the thickness of the layer P1 to be newly formed is defined.

In particular, in this embodiment, when a new layer P1 is formed on a previously formed layer P1, the stage 41 sequentially descends by a given amount under the command of the drive control section 22. In this manner, since the stage 41 is configured to be able to move in the Z direction (vertical direction), the number of members to be moved for adjusting the thickness of the layer P1 when the new layer P1 is formed can be decreased, and therefore, the structure of the shaped article production apparatus 100 can be further simplified.

The stage 41 has a flat surface (a region to which the composition P1′ is applied).

According to this, the layer P1 having a highly uniform thickness can be easily and reliably formed. Further, in the shaped article P10 to be produced, the occurrence of undesirable deformation or the like can be effectively prevented.

The stage 41 is preferably constituted by a material with a high strength. Examples of the constituent material of the stage 41 include various metal materials such as stainless steel.

Further, the surface (the region to which the composition P1′ is applied) of the stage 41 may be subjected to a surface treatment. By doing this, for example, the adhesion of the constituent material of the composition P1′ or the constituent material of the liquid composition P12 to the stage 41 is more effectively prevented, or the durability of the stage 41 is made more excellent, and thus, the stable production of the shaped article P10 can be achieved for a longer period of time. Examples of a material to be used for the surface treatment of the surface of the stage 41 include fluororesins such as polytetrafluoroethylene. Further, for the stage 41, for example, a material which is subjected to an alignment treatment such as polyimide can be used. According to this, the effect as described above is obtained.

The squeegee 42 has an elongated shape extending in the Y direction and includes a blade having a sharp edge shape at a lower tip end.

The length of the blade in the Y direction is equal to or longer than the width (the length in the Y direction) of the stage 41 (shaping region).

The shaped article production apparatus 100 may include a vibration mechanism (not shown) for giving small vibration to the blade so as to smoothly diffuse the composition P1′ with the squeegee 42.

The side surface support section 45 has a function to support the side surface of the layer P1 formed on the stage 41. The side surface support section 45 also has a function to define the area of the layer P1 when forming the layer P1.

Further, a surface (a region which can come in contact with the composition P1′) of the side surface support section 45 may be subjected to a surface treatment. By doing this, for example, the adhesion of the constituent material of the composition P1′ or the constituent material of the liquid composition P12 to the side surface support section 45 is more effectively prevented, or the durability of the side surface support section 45 is made more excellent, and thus, the stable production of the shaped article P10 can be achieved for a longer period of time. Further, when the previously formed layer P1 is moved relatively downward with respect to the side surface support section 45, the occurrence of an undesirable disturbance of the layer P1 can be effectively prevented. As a result, the dimensional accuracy and reliability of the finally obtained shaped article P10 can be made more excellent. Examples of a material to be used for the surface treatment of the surface of the side surface support section 45 include fluororesins such as polytetrafluoroethylene.

The liquid composition application unit (liquid composition ejection section) 5 applies the liquid composition P12 to the layer P1.

By including such a liquid composition application unit 5, the mechanical strength of the shaped article P10 can be easily and reliably made excellent.

In particular, in this embodiment, the liquid composition application unit 5 is a liquid composition ejection section which ejects the liquid composition P12 by an inkjet method.

According to this, the liquid composition P12 can be applied in a fine pattern, and even if the shaped article P10 has a fine structure, the shaped article P10 can be produced with higher productivity.

As a liquid droplet ejection system (a system of the inkjet method), a piezo system, a system for ejecting the liquid composition P12 by a bubble generated by heating the liquid composition P12, or the like can be used, however, from the viewpoint that the constituent components of the liquid composition P12 hardly undergo denaturation, and the like, a piezo system is preferred.

In the liquid composition ejection section (liquid composition application unit) 5, the pattern to be formed for each layer P1 and the amount of the liquid composition P12 to be applied to each part of the layer P1 are controlled by the command of the drive control section 22. The ejection pattern, the ejection amount, and the like of the liquid composition P12 by way of the liquid composition ejection section (liquid composition application unit) 5 are determined based on the slice data.

The energy ray irradiation unit (solidification unit or bond forming unit) 6 irradiates an energy ray for solidifying (curing) the liquid composition P12 applied to the layer P1.

In particular, in the configuration shown in the drawing, the energy ray irradiation unit (solidification unit or bond forming unit) 6 is provided on the upstream and downstream of the liquid composition ejection section (liquid composition application unit) 5 in a scanning direction (main scanning direction).

According to this, the bond formation can be performed by the energy ray irradiation unit (solidification unit or bond forming unit) 6 on both forward and backward paths, and therefore, the productivity of the shaped article P10 can be made more excellent.

Second Embodiment

Next, a second embodiment of the production apparatus (shaped article production apparatus) to be used for producing the shaped article according to the invention will be described.

FIG. 4 is a cross-sectional view schematically showing a second embodiment of the production apparatus to be used for producing the shaped article according to the invention. In the following description, different points from the above-mentioned embodiment will be mainly described, and the description of the same matter will be omitted.

A shaped article production apparatus 100 produces a shaped article (three-dimensionally shaped article) P10 by repeatedly forming a layer P1 using a tangible part forming ink P16′ and a support part forming ink P17′, and stacking the formed layers P1.

As shown in FIG. 4, the shaped article production apparatus 100 includes a control section 2, a stage 41, a tangible part forming ink application unit 8 which ejects the tangible part forming ink P16′ serving as the liquid composition, a support part forming ink application unit 9 which ejects the support part forming ink P17′, and an energy ray irradiation unit (solidification unit or bond forming unit) 6 which irradiates an energy ray for curing the tangible part forming ink P16′ and the support part forming ink P17′.

The tangible part forming ink application unit 8 ejects the tangible part forming ink P16′ by an inkjet method.

By including such a tangible part forming ink application unit 8, only a desired amount of the tangible part forming ink P16′ can be applied to a desired region in a fine pattern, and thus, even if the shaped article P10 has a fine structure, the shaped article P10 can be produced with higher productivity.

As a liquid droplet ejection system (a system of the inkjet method), a piezo system, a system for ejecting the ink by a bubble generated by heating the ink, or the like can be used, however, from the viewpoint that the constituent components of the ink hardly undergo denaturation, and the like, a piezo system is preferred.

In the tangible part forming ink application unit 8, the pattern to be formed, the amount of the tangible part forming ink P16′ to be applied, and the like are controlled by the command of the drive control section 22. The ejection pattern, the ejection amount, and the like of the tangible part forming ink P16′ by way of the tangible part forming ink application unit 8 are determined based on the slice data.

According to this, a necessary and sufficient amount of the tangible part forming ink P16′ can be applied to a target region, and thus, the tangible part P16 in a desired pattern can be reliably formed, and the dimensional accuracy and the mechanical strength of the shaped article P10 can be more reliably made excellent. Further, in the case where the tangible part forming ink P16′ contains a coloring agent, a desired color tone, design, and the like can be reliably obtained.

The tangible part forming ink application unit 8 is configured to be able to relatively move in the X and Y directions with respect to the stage, and also to be able to move in the Z direction.

According to this, even when the layers P1 are stacked, a distance between a nozzle surface (a tip end of an ejection section) of the tangible part forming ink application unit 8 and a place where the tangible part forming ink P16′ lands can be kept at a predetermined value.

The support part forming ink application unit 9 ejects the support part forming ink P17′ by an inkjet method.

By including such a support part forming ink application unit 9, only a desired amount of the support part forming ink P17′ can be applied to a desired region in a fine pattern, and thus, even if the shaped article P10 to be produced has a fine structure, the support part P17 having a desired size and a desired shape can be formed in a desired region, and the surface shape and appearance of the shaped article P10 can be more reliably controlled. Further, the productivity of the shaped article P10 can be made more excellent.

A liquid droplet ejection system (a system of the inkjet method), controlling, driving, etc. for the support part forming ink application unit 9 are the same as those for the tangible part forming ink application unit 8 described above.

Although not shown in the drawing, the shaped article production apparatus 100 may include a support part removal unit for removing the support part P17 and a drying unit for drying the shaped article P10 after removing the support part P17.

Examples of the support part removal unit include a unit which mechanically disrupts and removes the support part P17, a tank in which a liquid as described above is stored and the preform body P10′ is soaked, a liquid spraying unit which sprays a liquid as described above onto the preform body P10′, and a liquid application unit which applies a liquid as described above to the preform body P10′.

Examples of the drying unit include a unit which supplies a heated gas or a dried gas and a vacuum unit which reduces the pressure in a space in which the shaped article P10 is placed as described above.

Further, the shaped article production apparatus may perform at least part of the above-mentioned steps, and part of the above-mentioned steps may be performed without using the shaped article production apparatus.

Composition (Layer Forming Composition)

Next, a composition (layer forming composition) used in the embodiments of the production method for the shaped article (three-dimensionally shaped article) mentioned above will be described in detail.

First Embodiment

Hereinafter, the composition containing particles (particle-containing composition) P1′ as described in the production method and the shaped article production apparatus of the first embodiment mentioned above will be described.

The composition (particle-containing composition) P1′ contains at least a three-dimensional shaping powder containing a plurality of particles.

Three-Dimensional Shaping Powder (Particles)

Examples of a constituent material of the particles constituting the three-dimensional shaping powder include an inorganic material, an organic material, and a composite of these materials.

Examples of the inorganic material constituting the particles include various metals and metal compounds. Examples of the metal compounds include various metal oxides such as silica, alumina, titanium oxide, zinc oxide, zirconium oxide, tin oxide, magnesium oxide, and potassium titanate; various metal hydroxides such as magnesium hydroxide, aluminum hydroxide, and calcium hydroxide; various metal nitrides such as silicon nitride, titanium nitride, and aluminum nitride; various metal carbides such as silicon carbide and titanium carbide; various metal sulfides such as zinc sulfide; carbonates of various metals such as calcium carbonate and magnesium carbonate; sulfates of various metals such as calcium sulfate and magnesium sulfate; silicates of various metals such as calcium silicate and magnesium silicate; phosphates of various metals such as calcium phosphate; borates of various metals such as aluminum borate and magnesium borate; and composites of these materials.

Examples of the organic material constituting the particles include synthetic resins and natural polymers, and more specific examples thereof include a polyethylene resin; polypropylene; polyethylene oxide; polypropylene oxide; polyethylenimine; polystyrene; polyurethane; polyurea; polyester; a silicone resin; an acrylic silicone resin; a polymer containing a (meth)acrylate ester as a constituent monomer such as poly(methyl methacrylate); a crosspolymer (an ethylene acrylic acid copolymer resin or the like) containing a (meth)acrylate ester as a constituent monomer such as a methyl methacrylate crosspolymer; polyamide resins such as nylon 12, nylon 6, and copolymer nylon; polyimide; cellulose; cellulose derivatives such as carboxymethyl cellulose; gelatin; starch; chitin; and chitosan.

Above all, in the case where the particles are constituted by cellulose or a cellulose derivative (such as carboxymethyl cellulose), the affinity between the particles and the cellulosic material (in particular, the cellulose derivative as described above) contained in the liquid composition (ink) P12 or the affinity between the particles and the reactive ionic liquid contained in the liquid composition (ink) P12 can be made more excellent, and thus, the mechanical strength, durability, and reliability of the finally obtained shaped article P10 can be made excellent. Further, when the liquid composition P12 containing the cellulosic material and the reactive ionic liquid is applied to the layer P1, the liquid composition P12 can be effectively prevented from undesirably wetting and spreading, or the layer P1 can be effectively prevented from excessively repelling the liquid composition P12. As a result, the bound part (tangible part) P13 in a desired pattern can be more reliably formed, and thus, the dimensional accuracy of the shaped article P10 can be more reliably made more excellent.

The particles constituting the three-dimensional shaping powder may be subjected to a surface treatment such as a hydrophobization treatment or a hydrophilization treatment.

The average particle diameter of the particles constituting the three-dimensional shaping powder is not particularly limited, but is preferably 1 μm or more and 25 μm or less, more preferably 1 μm or more and 15 μm or less.

According to this, the mechanical strength of the shaped article P10 can be made more excellent, and also the occurrence of undesirable irregularities or the like in the shaped article P10 to be produced is more effectively prevented, and the dimensional accuracy of the shaped article P10 can be made more excellent. Further, the fluidity of the three-dimensional shaping powder and the fluidity of the composition containing the three-dimensional shaping powder (particle-containing composition) P1′ can be made more excellent, and thus, the productivity of the shaped article P10 can be made more excellent.

The Dmax of the particles constituting the three-dimensional shaping powder is preferably 3 μm or more and 40 μm or less, more preferably 5 μm or more and 30 μm or less. According to this, the mechanical strength of the shaped article P10 can be made more excellent, and also the occurrence of undesirable irregularities or the like in the shaped article P10 to be produced is more effectively prevented, and the dimensional accuracy of the shaped article P10 can be made more excellent. Further, the fluidity of the three-dimensional shaping powder and the fluidity of the composition containing the three-dimensional shaping powder (particle-containing composition) P1′ can be made more excellent, and thus, the productivity of the shaped article P10 can be made more excellent.

The particles constituting the three-dimensional shaping powder may have any shape, but preferably have a spherical shape. According to this, the fluidity of the three-dimensional shaping powder and the fluidity of the composition containing the three-dimensional shaping powder (particle-containing composition) P1′ can be made more excellent, and thus, the productivity of the shaped article P10 can be made more excellent, and also the occurrence of undesirable irregularities or the like in the shaped article P10 to be produced is more effectively prevented, and the dimensional accuracy of the shaped article P10 can be made more excellent.

The content of the three-dimensional shaping powder in the composition (particle-containing composition) P1′ is preferably 8% by mass or more and 95% by mass or less, more preferably 10% by mass or more and 75% by mass or less. According to this, while making the fluidity of the composition (particle-containing composition) P1′ sufficiently excellent, the mechanical strength of the finally obtained shaped article P10 can be made more excellent.

Solvent

The composition P1′ may contain a volatile solvent in addition to the components as described above.

According to this, the composition P1′ can be favorably transformed into a paste, and the fluidity of the composition P1′ can be stably made excellent, and the productivity of the shaped article P10 can be made more excellent.

In the case where the composition P1′ contains a binder (which will be described later), the solvent is preferably a solvent which dissolves the binder. According to this, the fluidity of the composition P1′ can be made favorable, and an undesirable variation in the thickness of the layer P1 to be formed using the composition P1′ can be more effectively prevented. Further, when the layer P1 in a state where the solvent is removed is formed, the binder can be adhered to the particles with higher uniformity throughout the entire layer P1, and thus, the occurrence of undesirable unevenness of the composition can be more effectively prevented. Due to this, the occurrence of an undesirable variation in the mechanical strength among individual regions of the finally obtained shaped article P10 can be more effectively prevented, and thus, the reliability of the shaped article P10 can be made higher.

Examples of the solvent constituting the composition P1′ include water; alcoholic solvents such as methanol, ethanol, and isopropanol; ketone-based solvents such as methyl ethyl ketone and acetone; glycol ether-based solvents such as ethylene glycol monoethyl ether and ethylene glycol monobutyl ether; glycol ether acetate-based solvents such as propylene glycol 1-monomethyl ether 2-acetate and propylene glycol 1-monoethyl ether 2-acetate; polyethylene glycol, and polypropylene glycol, and one solvent or a combination of two or more solvents selected from these can be used.

Above all, the composition P1′ preferably contains an aqueous solvent, more preferably contains water.

According to this, the fluidity of the composition P1′ and the uniformity of the composition of the layer P1 to be formed using the composition P1′ can be made more excellent. Further, water is easily removed after forming the layer P1, and also even if water remains in the shaped article P10, water hardly causes adverse effects. In addition, water is advantageous also from the viewpoint of safety for human beings, environmental problems, and the like. Further, in the case where the composition P1′ contains a water-soluble resin as a binder (which will be described in detail later), the water-soluble resin can be transformed into a more favorable dissolved state in the composition P1′, and therefore, the effect of including the binder (water-soluble resin) which will be described in detail later can be more effectively exhibited.

The aqueous solvent may be any as long as it is a solvent having high solubility in water, however, specifically, a solvent having a solubility in water (the mass of a solvent that can dissolve per 100 g of water) at 25° C. of 30 g/100 g of water or more is preferred, and a solvent having a solubility in water at 25° C. of 50 g/100 g of water or more is more preferred.

In the case where the composition P1′ contains a solvent, the content of the solvent in the composition P1′ is preferably 5% by mass or more and 92% by mass or less, more preferably 25% by mass or more and 89% by mass or less.

According to this, the effect of including the solvent as described above is more remarkably exhibited, and also the solvent can be easily removed in a short time in the production process for the shaped article P10, and thus, it is advantageous from the viewpoint of improvement of the productivity of the shaped article P10.

In particular, in the case where the composition P1′ contains water as the solvent, the content of water in the composition P1′ is preferably 18% by mass or more and 92% by mass or less, more preferably 47% by mass or more and 90% by mass or less.

According to this, the effect as described above is more remarkably exhibited.

In the case where the composition P1′ contains a solvent, the solvent is preferably removed from the composition P1′ constituting the layer P1 before the liquid composition P12 is applied.

According to this, the stability of the shape of the layer P1 is improved, and also even if the solvent has low affinity for the constituent material (for example, the cellulosic material, the reactive ionic liquid, or the like) of the liquid composition P12, undesirable repelling of the liquid composition P12 by the layer P1 or the like can be more effectively prevented, and thus, the liquid composition P12 can be more easily and more reliably applied in a desired pattern.

In the case where the solvent constituting the composition P1′ is removed from the composition P1′ constituting the layer P1 before the liquid composition P12 is applied, the solvent may be completely removed from the layer P1, or may be only partially removed from the layer P1. Even in such a case, the effect as described above is exhibited.

Binder

The composition P1′ may contain a binder.

According to this, a plurality of particles can be favorably bound (temporarily fixed) to one another in the layer P1 formed using the composition P1′ (particularly the layer P1 in a state where the solvent is removed), and thus, undesirable scattering or the like of the particles can be effectively prevented. As a result, the safety for workers and the dimensional accuracy of the shaped article P10 to be produced can be further improved.

In the case where the composition P1′ contains a binder, the binder is preferably dissolved in a solvent in the composition P1′.

According to this, the fluidity of the composition P1′ can be made more favorable, and an undesirable variation in the thickness of the layer P1 to be formed using the composition P1′ can be more effectively prevented. Further, when the layer P1 in a state where the solvent is removed is formed, the binder can be adhered to the particles with higher uniformity throughout the entire layer P1, and thus, the occurrence of undesirable unevenness of the composition can be more effectively prevented. Due to this, the occurrence of an undesirable variation in the mechanical strength among individual regions of the finally obtained shaped article P10 can be more effectively prevented, and thus, the reliability of the shaped article P10 can be made higher.

The binder may be any as long as it has a function to temporarily fix a plurality of particles in the layer P1 formed using the composition P1′ (particularly the layer P1 in a state where the solvent is removed), however, a water-soluble resin can be preferably used.

By including a water-soluble resin, in the case where the composition P1′ contains an aqueous solvent (particularly water) as the solvent, the binder (water-soluble resin) can be included in the composition P1′ in a dissolved state, and the fluidity and handleability (ease of handling) of the composition P1′ can be made more excellent. As a result, the productivity of the shaped article P10 can be made more excellent.

Further, by applying an aqueous solvent (particularly water) to a region of the layer P1 where the liquid composition P12 is not applied in the production process for the shaped article P10, the region can be easily and efficiently removed. As a result, the productivity of the shaped article P10 can be made more excellent. Further, the region of the layer which should be removed can be easily and reliably prevented from adhering to or remaining in the finally obtained shaped article P10, and thus, the dimensional accuracy of the shaped article P10 can be made more excellent.

Hereinafter, the water-soluble resin as the binder will be mainly described.

The water-soluble resin may be any as long as it can at least partially dissolve in an aqueous solvent, but is preferably, for example, a resin having a solubility in water (the mass of a resin that can dissolve per 100 g of water) at 25° C. of 5 g/100 g of water or more, more preferably a resin having a solubility in water at 25° C. of 10 g/100 g of water or more.

Examples of the water-soluble resin include synthetic polymers such as polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polycaprolactone diol, sodium polyacrylate, polyacrylamide, modified polyamide, polyethylenimine, polyethylene oxide, and a random copolymer of ethylene oxide and propylene oxide; natural polymers such as corn starch, mannan, pectin, agar, alginic acid, dextran, glue, and gelatin; and semisynthetic polymers such as carboxymethyl cellulose, hydroxyethyl cellulose, starch, oxidized starch, and modified starch, and one material or a combination of two or more materials selected from these can be used.

Specific examples of a water-soluble resin product include methyl cellulose (Metolose SM-15, manufactured by Shin-Etsu Chemical Co., Ltd.), hydroxyethyl cellulose (AL-15, manufactured by FUJI Chemical, Inc.), hydroxypropyl cellulose (HPC-M, manufactured by Nippon Soda Co., Ltd.), carboxymethyl cellulose (CMC-30, manufactured by Nichirin Chemical Industries, Ltd.), sodium starch phosphate ester (I) (Hosuta 5100, manufactured by Matsutani Chemical Industry Co., Ltd.), polyvinylpyrrolidone (PVP K-90, manufactured by Tokyo Chemical Industry Co., Ltd.), a copolymer of methyl vinyl ether/maleic anhydride (Gantrez AN-139, manufactured by GAF Corporation), polyacrylamide (manufactured by Wako Pure Chemical Industries, Ltd.), modified polyamide (modified nylon) (AQ nylon, manufactured by Toray Industries, Inc.), polyethylene oxide (PEO-1, manufactured by Seitetsu Kagaku Co., Ltd., Alkox, manufactured by Meisei Chemical Works, Ltd.), a random copolymer of ethylene oxide and propylene oxide (Alkox EP, manufactured by Meisei Chemical Works, Ltd.), sodium polyacrylate (manufactured by Wako Pure Chemical Industries, Ltd.), and a carboxyvinyl polymer/cross-linked acrylic water-soluble resin (Aqupec, manufactured by Sumitomo Seika Chemicals Co., Ltd.).

Above all, in the case where the water-soluble resin as the binder is polyvinyl alcohol, the mechanical strength of the shaped article P10 can be made more excellent. Further, by adjusting the saponification degree or the polymerization degree, the properties (for example, water solubility, water resistance, etc.) of the binder and the properties (for example, viscosity, the ability to fix the particles, wettability, etc.) of the composition P1′ can be more favorably controlled. Due to this, polyvinyl alcohol can be more favorably applied to the production of a variety of shaped articles P10. Further, polyvinyl alcohol is inexpensive and offers a stable supply among the various water-soluble resins. Due to this, while keeping the production cost low, the shaped article P10 can be stably produced.

In the case where the water-soluble resin as the binder contains polyvinyl alcohol, the saponification degree of the polyvinyl alcohol is preferably 85 or more and 90 or less. According to this, a decrease in the solubility of polyvinyl alcohol in an aqueous solvent (particularly water) can be prevented. Due to this, in the case where the composition P1′ contains an aqueous solvent (particularly water), a decrease in the adhesiveness between adjacent layers P1 can be more effectively prevented.

In the case where the water-soluble resin as the binder contains polyvinyl alcohol, the polymerization degree of the polyvinyl alcohol is preferably 300 or more and 1,000 or less. According to this, in the case where the composition P1′ contains an aqueous solvent (particularly water), the mechanical strength of the respective layers P1 and the adhesiveness between adjacent layers P1 can be made more excellent.

Further, in the case where the water-soluble resin as the binder is polyvinylpyrrolidone (PVP), effects as described below are obtained. That is, polyvinylpyrrolidone has excellent adhesiveness to various materials such as a glass, a metal, and a plastic, and therefore, the strength and the stability of the shape of a portion of the layer P1 to which the liquid composition P12 is not applied can be made more excellent, and the dimensional accuracy of the finally obtained shaped article P10 can be made more excellent. Further, polyvinylpyrrolidone shows high solubility in water, and therefore, in an unbound particle removal step (after completion of shaping), among the particles constituting the respective layers P1, the particles which are not bound to one another by the reaction product of the reactive ionic liquid or the like can be easily and reliably removed. Further, polyvinylpyrrolidone has moderate affinity for the three-dimensional shaping powder as described above, and therefore has relatively high wettability to the surfaces of the particles. Due to this, the function to temporarily fix the particles as described above can be more effectively exhibited. Further, polyvinylpyrrolidone has excellent affinity for various coloring agents, and therefore, in the case where the liquid composition P12 containing a coloring agent is used in the liquid composition application step, undesirable diffusion of the coloring agent can be effectively prevented. Further, in the case where the composition P1′ in the form of a paste contains polyvinylpyrrolidone, the inclusion of a bubble in the composition P1′ can be effectively prevented, and in the layer forming step, the occurrence of defects due to the inclusion of a bubble can be more effectively prevented.

In the case where the water-soluble resin as the binder contains polyvinylpyrrolidone, the weight average molecular weight of the polyvinylpyrrolidone is preferably 10,000 or more 1,700,000 or less, more preferably 30,000 or more 1,500,000 or less.

According to this, the above-mentioned function can be more effectively exhibited.

Further, in the case where the water-soluble resin is polycaprolactone diol, the composition P1′ can be favorably transformed into pellets, and undesirable scattering or the like of the particles can be more effectively prevented, and the handleability (ease of handling) of the composition P1′ is improved, so that the safety for workers and the dimensional accuracy of the shaped article P10 to be produced can be improved. Further, melting can be achieved at a relatively low temperature, and thus, the energy and cost required for the production of the shaped article P10 can be kept low, and also the productivity of the shaped article P10 can be made sufficiently excellent.

In the case where the water-soluble resin as the binder contains polycaprolactone diol, the weight average molecular weight of the polycaprolactone diol is preferably 10,000 or more 1,700,000 or less, more preferably 30,000 or more 1,500,000 or less.

According to this, the above-mentioned function can be more effectively exhibited.

In the composition P1′, the binder is preferably in a liquid state (for example, in a dissolved state, in a molten state, or the like) in the layer forming step.

According to this, the uniformity of the thickness of the layer P1 to be formed using the composition P1′ can be easily and reliably made higher.

In the case where the composition P1′ contains a binder, the content of the binder in the composition P1′ is preferably 0.5% by mass or more and 25% by mass or less, more preferably 1.0% by mass or more and 10% by mass or less.

According to this, the effect of including the binder as described above is more remarkably exhibited, and also the content of the particles and the like in the composition P1′ can be made sufficiently high, and thus, the mechanical strength and the like of the shaped article P10 to be produced can be made more excellent.

Another Component

The composition P1′ may contain a component other than the above-mentioned components. Examples of such a component include a polymerization initiator, a polymerization accelerator, a crosslinking agent, a siloxane compound, a permeation accelerator, a wetting agent (humectant), a fixing agent, an antifungal agent, a preservative, an antioxidant, an ultraviolet absorbing agent, a chelating agent, and a pH adjusting agent.

Second Embodiment

Hereinafter, the composition (layer forming composition) to be ejected by an inkjet method as described in the production method and the shaped article production apparatus of the second embodiment mentioned above will be described.

In this embodiment, as the composition, a tangible part forming ink P16′ and a support part forming ink P17′ are used.

The tangible part forming ink P16′ has been described in detail as the liquid composition containing a cellulosic material and a reactive ionic liquid, and therefore, hereinafter, the support part forming ink P17′ will be described in detail.

Support Part Forming Ink

The support part forming ink P17′ contains at least a curable resin (curable component).

Curable Resin

Examples of the curable resin (curable component) constituting the support part forming ink P17′ include the same curable resins (curable components) as those exemplified as the constituent component (curable component as another component) of the tangible part forming ink P16′.

In particular, it is preferred to cure the curable resin (curable component) constituting the support part forming ink P17′ and the curable component (curable component as another component) constituting the tangible part forming ink P16′ described above by the same type of energy ray.

According to this, the structure of the production apparatus to be used for producing the shaped article can be effectively prevented from being complicated, and thus, the productivity of the shaped article P10 can be made more excellent. Further, the surface shape of the shaped article P10 can be more reliably controlled.

The support part forming ink P17′ preferably contains one or more curable components particularly selected from the group consisting of tetrahydrofurfuryl(meth)acrylate, ethoxyethoxyethyl(meth)acrylate, polyethylene glycol di(meth)acrylate, and (meth)acryloyl morpholine among various curable components.

According to this, while more reliably making the appearance of the shaped article P10 excellent, the productivity of the shaped article P10 can be made more excellent.

Further, the mechanical strength and the stability of the shape of the support part P17 to be formed by curing the support part forming ink P17′ can be made more excellent. As a result, when producing the shaped article P10, the support part P17 as the lower layer (first layer) can more favorably support the tangible part forming ink P16′ for forming the upper layer (second layer). Due to this, undesirable deformation (particularly, sagging or the like) of the tangible part P16 can be more favorably prevented, and thus, the dimensional accuracy of the finally obtained shaped article P10 can be made more excellent.

In particular, when the support part forming ink P17′ contains (meth)acryloyl morpholine, an effect as described below is obtained.

That is, when (meth)acryloyl morpholine is in a state of being not completely cured even if a curing reaction has proceeded (a polymer of (meth)acryloyl morpholine in a state of being not completely cured), (meth)acryloyl morpholine is in a state of having high solubility in various solvents such as water. Therefore, in the support section removal step as described above, while more effectively preventing the occurrence of defects in the tangible part P16, the support part P17 can be selectively and reliably, and also efficiently removed. As a result, the shaped article P10 having a desired form can be obtained with high productivity and higher reliability.

Further, when the support part forming ink P17′ contains tetrahydrofurfuryl(meth)acrylate, the flexibility after curing can be maintained more favorably, and in a treatment with a liquid for removing the support part P17, the support part P17 is more easily transformed into a gel, and therefore, the efficiency of removal of the support part P17 can be further enhanced.

Further, when the support part forming ink P17′ contains ethoxyethoxyethyl(meth)acrylate, in a treatment with a liquid for removing the support part P17, the efficiency of removal of the support part P17 can be enhanced.

Further, when the support part forming ink P17′ contains polyethylene glycol di(meth)acrylate, in the case where a liquid for removing the support part P17 contains water as a main component, the solubility of the support part P17 in the liquid is increased, and thus, the support part P17 can be more easily removed.

The content of the curable component in the support part forming ink P17′ is preferably 83% by mass or more and 98.5% by mass or less, more preferably 87% by mass or more and 95.4% by mass or less.

According to this, the stability of the shape of the support part P17 to be formed can be made more excellent, and in the case where the layers P1 are stacked when producing the shaped article P10, undesirable deformation of the layer P1 on the lower side can be more effectively prevented, and the layer P1 on the upper side can be favorably supported. As a result, the dimensional accuracy of the finally obtained shaped article P10 can be made more excellent. Further, the productivity of the shaped article P10 can be made more excellent.

Polymerization Initiator

The support part forming ink P17′ preferably contains a polymerization initiator.

According to this, the curing speed of the support part forming ink P17′ when producing the shaped article P10 can be moderately increased, and thus, the productivity of the shaped article P10 can be made more excellent.

Further, the stability of the shape of the support part P17 to be formed can be made more excellent, and in the case where the layers P1 are stacked when producing the shaped article P10, undesirable deformation of the layer P1 on the lower side can be more effectively prevented, and the layer P1 on the upper side can be favorably supported. As a result, the dimensional accuracy of the finally obtained shaped article P10 can be made more excellent.

Examples of the polymerization initiator constituting the support part forming ink P17′ include the same polymerization initiators as those exemplified as the constituent component of the tangible part forming ink P16′.

In particular, the support part forming ink P17′ preferably contains at least either of bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide as the polymerization initiator.

By including such a polymerization initiator, while more reliably making the properties of the surface of the tangible part P16 (the tangible part P16 to be formed using the tangible part forming ink P16′) which is formed in contact with the support part P17 (the support part P17 to be formed using the support part forming ink P17′) favorable, and also while more reliably making the appearance of the shaped article P10 excellent, the productivity of the shaped article P10 can be made more excellent.

In addition, the mechanical strength and the stability of the shape of the support part P17 to be formed by curing the support part forming ink P17′ can be made more excellent. As a result, when producing the shaped article P10, the support part P17 as the lower layer (first layer) can more favorably support the tangible part forming ink P16′ for forming the upper layer (second layer). Due to this, undesirable deformation (particularly, sagging or the like) of the tangible part P16 can be more favorably prevented, and thus, the dimensional accuracy of the finally obtained shaped article P10 can be made more excellent.

A specific value of the content of the polymerization initiator in the support part forming ink P17′ is preferably 1.5% by mass or more and 17% by mass or less, more preferably 4.6% by mass or more and 13% by mass or less.

According to this, while more reliably making the appearance of the shaped article P10 excellent, the productivity of the shaped article P10 can be made more excellent.

Further, the mechanical strength and the stability of the shape of the support part P17 to be formed by curing the support part forming ink P17′ can be made more excellent. As a result, when producing the shaped article P10, the support part P17 as the lower layer (first layer) can more favorably support the tangible part forming ink P16′ for forming the upper layer (second layer). Due to this, undesirable deformation (particularly, sagging or the like) of the tangible part P16 can be more favorably prevented, and thus, the dimensional accuracy of the finally obtained shaped article P10 can be made more excellent.

Another Component

The support part forming ink P17′ may contain a component other than the above-mentioned components. Examples of such a component include various coloring agents such as a pigment and a dye, a dispersant, a surfactant, a sensitizer, a polymerization accelerator, a solvent, a permeation accelerator, a wetting agent (humectant), a fixing agent, an antifungal agent, a preservative, an antioxidant, an ultraviolet absorbing agent, a chelating agent, a pH adjusting agent, a thickening agent, a filler, an anti-aggregation agent, and a defoaming agent.

In particular, by including a coloring agent in the support part forming ink P17′, the visibility of the support part P17 is improved, and in the finally obtained shaped article P10, at least a portion of the support part P17 can be more reliably prevented from undesirably remaining.

Examples of the coloring agent constituting the support part forming ink P17′ include the same coloring agents as those exemplified as the constituent component of the tangible part forming ink P16′, however, the coloring agent is preferably a coloring agent which gives a color different from the color of the tangible part P16 (a color of the shaped article P10 to be visually recognized in appearance) superimposed on the support part P17 formed using the support part forming ink P17′ when observed from the normal direction of the surface of the shaped article P10. According to this, the effect as described above is more remarkably exhibited.

In the case where the support part forming ink P17′ contains a pigment, if the support part forming ink P17′ further contains a dispersant, the dispersibility of the pigment can be made more favorable. Examples of the dispersant constituting the support part forming ink P17′ include the same dispersants as those exemplified as the constituent component of the tangible part forming ink P16′.

The viscosity of the support part forming ink P17′ is preferably 2 mPa·s or more and 30 mPa·s or less, more preferably 5 mPa·s or more and 20 mPa·s or less.

According to this, the ejection stability of the support part forming ink P17′ by an inkjet method can be made more excellent.

In the production of the shaped article P10, a plurality of types of support part forming inks P17′ may be used.

Hereinabove, preferred embodiments of the invention have been described, however, the invention is not limited thereto.

For example, in the above-mentioned embodiments, a case where a squeegee is used as the flattening unit has been mainly described, however, a roller or the like may be used in place of the squeegee.

Further, the production apparatus to be used for producing the shaped article according to the invention may include a recovery mechanism (not shown) for recovering the composition which is not used for forming the layer in the composition supplied from the composition supply section. According to this, while preventing the accumulation of the excess composition in a region where the layer is formed, a sufficient amount of the composition can be supplied, and therefore, the occurrence of defects in the layer is more effectively prevented, and the shaped article can be produced more stably. Further, the recovered composition can be used for producing the shaped article again, and therefore, this can contribute to the reduction in the production cost of the shaped article, so that this configuration is preferred also from the viewpoint of resource saving.

Further, the production apparatus to be used for producing the shaped article according to the invention may include a recovery mechanism for recovering the composition removed in the unbound particle removal step.

Further, in the above-mentioned embodiments, a case where the tangible part is formed in all the layers has been described, however, a layer in which the tangible part is not formed may be formed. For example, the tangible part is not formed in a layer formed immediately above the stage, and the layer may be made to function as a sacrifice layer.

Further, in the above-mentioned embodiments, a case where the ink application step is performed by an inkjet method has been mainly described, however, the ink application step may be performed using another method (for example, another printing method).

Further, the tangible part forming ink and the support part forming ink may be applied by a method other than the inkjet method (for example, another printing method).

Further, in the above-mentioned embodiments, a case where in addition to the layer forming step and the liquid composition application step (ink application step), the solidification step is also performed repeatedly along with the layer forming step and the ink application step has been described, however, the solidification step may not be performed repeatedly. For example, after forming a stacked body including a plurality of layers which have not been subjected to a solidification treatment for solidifying the liquid composition, the plurality of layers are subjected to the solidification treatment all together. According to this, for example, a treatment of applying an energy for solidifying (curing) the liquid composition can be reduced, and therefore, even in the case of using a material having low resistance to the energy in the production of the shaped article, undesirable denaturation, deterioration, or the like by application of the energy can be effectively prevented.

In the invention, it is only necessary to use the liquid composition containing the cellulosic material and the reactive ionic liquid for forming at least a portion of the tangible part of the shaped article, and the tangible part may have a portion which is formed without using the liquid composition.

Further, in the production of the shaped article according to the invention, a pre-treatment step, an intermediate treatment step, or a post-treatment step may be performed as needed.

Examples of the pre-treatment step include a stage cleaning step.

As the intermediate treatment step, for example, in the case where the layer forming composition is in the form of pellets, a step of stopping heating or the like (a binder solidification step) may be included between the layer forming step and the liquid composition application step. According to this, the binder constituting the pellets is transformed into a solid state, and the layer can be obtained as a layer in which the binding strength between the particles is higher. Further, for example, in the case where the layer forming composition contains a solvent component (dispersion medium) such as water, a solvent component removal step in which the solvent component is removed may be included between the layer forming step and the liquid composition application step. According to this, the layer forming step can be performed more smoothly, and an undesirable variation in the thickness of the layer to be formed can be more effectively prevented. As a result, the shaped article having higher dimensional accuracy can be produced with higher productivity.

Examples of the post-treatment step include a washing step, a shape adjustment step in which deburring or the like is performed, a coloring step, and a coating layer forming step.

Further, in the above-mentioned embodiments, a case where the flattening unit moves on the stage has been described, however, the flattening may be performed by moving the stage so as to change the positional relationship between the stage and the squeegee.

Further, in the above-mentioned embodiments, a case where the shaped article production apparatus includes an energy ray irradiation unit which irradiates an energy ray as the solidification unit has been representatively described, however, the solidification unit included in the shaped article production apparatus may be another unit such as a heating unit.

Further, the shaped article according to the invention may be any as long as it is produced using the liquid composition according to the invention, and may not be produced using the above-mentioned method or apparatus.

Further, in the above-mentioned embodiments, in the case where the cellulose derivative has a reactive functional group which reacts with a siloxane compound, a crosslinking agent, or the like, or the case where the reactive ionic liquid is a reactive ionic liquid which reacts with a siloxane compound, a crosslinking agent, or the like, a case where a reactive component such as a siloxane compound or a crosslinking agent is contained in the liquid composition has been mainly described, however, the reaction component may not be contained in the liquid composition, and for example, the reaction component may come in contact with the cellulose derivative or the reactive ionic liquid when it reacts with the cellulose derivative or the reactive ionic liquid.

Further, when the shaped article according to the invention is produced, a chemical reaction other than the above-mentioned chemical reaction may be performed. For example, in the case where the liquid composition contains a cellulose derivative having an acetylated hydroxy group, a reaction to release the acetyl group (deacetylation reaction) may be performed in the production of the shaped article. According to this, for example, in the liquid composition, while making the hydrophobicity of the cellulosic material (cellulose derivative) higher, the hydrophobicity of the finally obtained shaped article can be made relatively low, and thus, the properties of the shaped article can be made compatible with the productivity of the shaped article and the storage stability of the liquid composition. 

What is claimed is:
 1. A liquid composition comprising: a cellulosic material comprising a cellulose derivative including hydroxyl groups, with at least a part of the hydroxyl groups of the cellulose derivative being substituted with both (i) an imidazole-based ionic moiety and (ii) a liquid crystalline functional group represented by either formula (10) or (11) such that the cellulose derivative has the following structure

wherein l, m, and n are each independently an integer of 2 or more, R¹, R², R⁴, and R⁵ are each independently a hydrogen atom or a acetyl group, R⁸ is represented by formula (9) below and R⁹ is either formula (10) or (11), below:

wherein in formula (9), k is an integer of 1 or more, and R⁷ is a hydrogen atom or an alkyl group; wherein in formula (10) and (11), j is an integer of 1 or more and R⁶ is a hydrogen atom or an alkyl group; and an ionic liquid having a reactive functional group.
 2. The liquid composition according to claim 1, wherein the ionic liquid comprises an imidazolium salt.
 3. The liquid composition according to claim 1, wherein the reactive functional group contains a carbon-carbon double bond.
 4. The liquid composition according to claim 3, wherein the reactive functional group is a (meth)acryloyl group.
 5. The liquid composition according to claim 1, wherein the liquid composition satisfies the following relationship: 1≦Xc/Xs≦40, where Xs is the content of the ionic liquid in mass % and Xc is the content of the cellulosic material in mass %.
 6. A shaped article, wherein the shaped article is produced using the liquid composition according to claim
 1. 7. A shaped article, wherein the shaped article is produced using the liquid composition according to claim
 2. 8. A shaped article, wherein the shaped article is produced using the liquid composition according to claim
 3. 9. A shaped article, wherein the shaped article is produced using the liquid composition according to claim
 4. 10. A shaped article, wherein the shaped article is produced using the liquid composition according to claim
 5. 11. A method for producing a shaped article, the method comprising: forming a layer using the liquid composition according to claim 1 a plurality of times and stacking the layers, wherein the liquid composition is applied to a region where a three-dimensionally shaped article is to be formed; and following stacking the layers, allowing a chemical reaction involving a functional group of the liquid composition to proceed.
 12. The method according to claim 11, wherein the liquid composition is applied by an inkjet method.
 13. The liquid composition according to claim 1, wherein the ionic liquid contains an imidazole group.
 14. The liquid composition according to claim 1, wherein the liquid composition satisfies the following relationship: 1.5≦Xc/Xs≦2.5, where Xs is the content of the ionic liquid in mass % and Xc is the content of the cellulosic material in mass %.
 15. A shaped article, wherein the shaped article is produced using the liquid composition according to claim
 13. 